diff --git a/nmrpy/data_objects.py b/nmrpy/data_objects.py
index 80ac019..ed11e97 100644
--- a/nmrpy/data_objects.py
+++ b/nmrpy/data_objects.py
@@ -14,6 +14,7 @@
 from sdRDM import DataModel
 from sdRDM.base.importedmodules import ImportedModules
 from nmrpy.datamodel.core import *
+from nmrpy.utils import create_enzymeml
 
 
 class Base:
@@ -514,10 +515,24 @@ def deconvoluted_integrals(self):
         """
         if self._deconvoluted_peaks is not None:
             integrals = []
+            i = 0
             for peak in self._deconvoluted_peaks:
                 int_gauss = peak[-1] * Fid._f_gauss_int(peak[3], peak[1])
                 int_lorentz = (1 - peak[-1]) * Fid._f_lorentz_int(peak[3], peak[2])
                 integrals.append(int_gauss + int_lorentz)
+
+                for peak_identity in self.fid_object.peak_identities:
+                    if peak_identity.name == self.identities[i]:
+                        try:
+                            peak_identity.associated_integrals.append(
+                                float(integrals[i])
+                            )
+                        except:
+                            peak_identity.associated_integrals = []
+                            peak_identity.associated_integrals.append(
+                                float(integrals[i])
+                            )
+                i += 1
             return integrals
 
     def _get_plots(self):
@@ -1509,6 +1524,24 @@ def enzymeml_library(self):
         del self.__enzymeml_library
         print("The current EnzymeML library has been deleted.")
 
+    @property
+    def concentrations(self):
+        """
+        An array of the concentration for each FID.
+        """
+        return self.__c
+
+    @concentrations.setter
+    def concentrations(self, c):
+        if not isinstance(c, dict):
+            raise TypeError("c must be a dictionary.")
+        self.__c = c
+
+    @concentrations.deleter
+    def concentrations(self):
+        del self.__c
+        print("The current concentrations have been deleted.")
+
     def __str__(self):
         return "FidArray of {} FID(s)".format(len(self.data))
 
@@ -1568,6 +1601,7 @@ def _get_widgets(self):
             or isinstance(self.__dict__[id], FidArrayRangeSelector)
             or isinstance(self.__dict__[id], DataTraceRangeSelector)
             or isinstance(self.__dict__[id], DataTraceSelector)
+            or isinstance(self.__dict__[id], IdentityRangeAssigner)
         ]
         return widgets
 
@@ -2325,14 +2359,22 @@ def save_to_file(self, filename=None, overwrite=False):
         self._del_widgets()
         for fid in self.get_fids():
             fid._del_widgets()
+        # delete EnzymeML library & document (can't be pickled)
+        try:
+            del self.enzymeml_library
+            del self.enzymeml_document
+        except:
+            pass
         with open(filename, "wb") as f:
             pickle.dump(self, f)
 
     # TODO: Will probably create a measurement object for each FID(?)
     # and add them to the EnzymeML document provided
     # Issue: How to get species for IdentityAssigner? __init__()?
-    def add_to_enzymeml(self, enzymeml_document=None) -> None:
-        ...
+    def to_enzymeml(self, enzymeml_document: DataModel = None) -> DataModel:
+        if not enzymeml_document:
+            enzymeml_document = self.enzymeml_document
+        return create_enzymeml(self, enzymeml_document)
 
     # TODO: Refactor save_data method
     # possibly make saving to EnzymeML a get_measurements method
@@ -2409,6 +2451,12 @@ def clear_identities(self):
         for fid in self.get_fids():
             fid.identities = None
 
+    def calculate_concentrations(self):
+        integrals = self.deconvoluted_integrals.transpose()
+        self._concentration_widget = ConcentrationCalculator(
+            fid_array=self, integrals=integrals
+        )
+
 
 class Importer(Base):
     def __init__(self, *args, **kwargs):
diff --git a/nmrpy/datamodel/__init__.py b/nmrpy/datamodel/__init__.py
index 08352f9..d866ab2 100644
--- a/nmrpy/datamodel/__init__.py
+++ b/nmrpy/datamodel/__init__.py
@@ -1,3 +1,3 @@
 
-__URL__ = "https://github.com/NMRPy/nmrpy"
-__COMMIT__ = "dec2cda6676f8d04070715fe079ed786515ea918"
+__URL__ = ""
+__COMMIT__ = ""
diff --git a/nmrpy/datamodel/core/__init__.py b/nmrpy/datamodel/core/__init__.py
index 7027d43..f22d8a0 100644
--- a/nmrpy/datamodel/core/__init__.py
+++ b/nmrpy/datamodel/core/__init__.py
@@ -5,17 +5,12 @@
 from .processingsteps import ProcessingSteps
 from .identity import Identity
 from .fidarray import FIDArray
-from .citation import Citation
-from .person import Person
-from .publication import Publication
 from .cv import CV
 from .term import Term
 from .fileformats import FileFormats
-from .subjects import Subjects
-from .publicationtypes import PublicationTypes
-from .identifiertypes import IdentifierTypes
 
 __doc__ = ""
+
 __all__ = [
     "NMRpy",
     "Experiment",
@@ -24,13 +19,7 @@
     "ProcessingSteps",
     "Identity",
     "FIDArray",
-    "Citation",
-    "Person",
-    "Publication",
     "CV",
     "Term",
     "FileFormats",
-    "Subjects",
-    "PublicationTypes",
-    "IdentifierTypes",
 ]
diff --git a/nmrpy/datamodel/core/abstractspecies.py b/nmrpy/datamodel/core/abstractspecies.py
deleted file mode 100644
index 57e50eb..0000000
--- a/nmrpy/datamodel/core/abstractspecies.py
+++ /dev/null
@@ -1,71 +0,0 @@
-import sdRDM
-
-from typing import Optional, Union
-from pydantic import Field, validator
-from sdRDM.base.utils import forge_signature, IDGenerator
-
-from pydantic import StrictBool
-
-from .vessel import Vessel
-
-
-@forge_signature
-class AbstractSpecies(sdRDM.DataModel):
-    """This object is used to inherit basic attributes common to all species used in the data model."""
-
-    id: Optional[str] = Field(
-        description="Unique identifier of the given object.",
-        default_factory=IDGenerator("abstractspeciesINDEX"),
-        xml="@id",
-    )
-
-    name: str = Field(
-        ...,
-        description="None",
-    )
-
-    vessel_id: Union[Vessel, str] = Field(
-        ...,
-        reference="Vessel.id",
-        description="None",
-    )
-
-    init_conc: Optional[float] = Field(
-        default=None,
-        description="None",
-    )
-
-    constant: StrictBool = Field(
-        ...,
-        description="None",
-    )
-
-    unit: Optional[str] = Field(
-        default=None,
-        description="None",
-    )
-
-    uri: Optional[str] = Field(
-        default=None,
-        description="None",
-    )
-
-    creator_id: Optional[str] = Field(
-        default=None,
-        description="None",
-    )
-
-    @validator("vessel_id")
-    def get_vessel_id_reference(cls, value):
-        """Extracts the ID from a given object to create a reference"""
-
-        from .vessel import Vessel
-
-        if isinstance(value, Vessel):
-            return value.id
-        elif isinstance(value, str):
-            return value
-        else:
-            raise TypeError(
-                f"Expected types [Vessel, str] got '{type(value).__name__}' instead."
-            )
diff --git a/nmrpy/datamodel/core/citation.py b/nmrpy/datamodel/core/citation.py
deleted file mode 100644
index c7834f3..0000000
--- a/nmrpy/datamodel/core/citation.py
+++ /dev/null
@@ -1,216 +0,0 @@
-import sdRDM
-
-from typing import Any, List, Optional
-from pydantic import AnyUrl, Field, PrivateAttr
-from sdRDM.base.listplus import ListPlus
-from sdRDM.base.utils import forge_signature, IDGenerator
-from .identifiertypes import IdentifierTypes
-from .person import Person
-from .publicationtypes import PublicationTypes
-from .subjects import Subjects
-from .term import Term
-from .publication import Publication
-
-
-@forge_signature
-class Citation(sdRDM.DataModel):
-    """Container for various types of metadata primarily used in the publication and citation of the dataset."""
-
-    id: Optional[str] = Field(
-        description="Unique identifier of the given object.",
-        default_factory=IDGenerator("citationINDEX"),
-        xml="@id",
-    )
-
-    title: Optional[str] = Field(
-        default=None,
-        description="Title the dataset should have when published.",
-    )
-
-    doi: Optional[AnyUrl] = Field(
-        default=None,
-        description="DOI pointing to the published dataset",
-    )
-
-    description: Optional[str] = Field(
-        default=None,
-        description="Description the dataset should have when published.",
-    )
-
-    authors: List[Person] = Field(
-        description="List of authors for this dataset.",
-        default_factory=ListPlus,
-        multiple=True,
-    )
-
-    subjects: List[Subjects] = Field(
-        description="List of subjects this dataset belongs to.",
-        default_factory=ListPlus,
-        multiple=True,
-    )
-
-    keywords: List[Term] = Field(
-        description="List of CV-based keywords describing the dataset.",
-        default_factory=ListPlus,
-        multiple=True,
-    )
-
-    topics: List[Term] = Field(
-        description="List of CV-based topics the dataset addresses.",
-        default_factory=ListPlus,
-        multiple=True,
-    )
-
-    related_publications: List[Publication] = Field(
-        description="List of publications relating to this dataset.",
-        default_factory=ListPlus,
-        multiple=True,
-    )
-
-    notes: Optional[str] = Field(
-        default=None,
-        description="Additional notes about the dataset.",
-    )
-
-    funding: List[str] = Field(
-        description="Funding information for this dataset.",
-        default_factory=ListPlus,
-        multiple=True,
-    )
-
-    license: Optional[str] = Field(
-        default="CC BY 4.0",
-        description="License information for this dataset. Defaults to `CC BY 4.0`.",
-    )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
-
-    def add_to_authors(
-        self,
-        last_name: str,
-        first_name: str,
-        middle_names: List[str] = ListPlus(),
-        affiliation: Optional[str] = None,
-        email: Optional[str] = None,
-        identifier_type: Optional[IdentifierTypes] = None,
-        identifier_value: Optional[str] = None,
-        id: Optional[str] = None,
-    ) -> None:
-        """
-        This method adds an object of type 'Person' to attribute authors
-
-        Args:
-            id (str): Unique identifier of the 'Person' object. Defaults to 'None'.
-            last_name (): Family name of the person..
-            first_name (): Given name of the person..
-            middle_names (): List of middle names of the person.. Defaults to ListPlus()
-            affiliation (): Institution the Person belongs to.. Defaults to None
-            email (): Email address of the person.. Defaults to None
-            identifier_type (): Recognized identifier for the person.. Defaults to None
-            identifier_value (): Value of the identifier for the person.. Defaults to None
-        """
-        params = {
-            "last_name": last_name,
-            "first_name": first_name,
-            "middle_names": middle_names,
-            "affiliation": affiliation,
-            "email": email,
-            "identifier_type": identifier_type,
-            "identifier_value": identifier_value,
-        }
-        if id is not None:
-            params["id"] = id
-        self.authors.append(Person(**params))
-        return self.authors[-1]
-
-    def add_to_keywords(
-        self,
-        name: str,
-        accession: str,
-        term_cv_reference: Optional[str] = None,
-        value: Optional[Any] = None,
-        id: Optional[str] = None,
-    ) -> None:
-        """
-        This method adds an object of type 'Term' to attribute keywords
-
-        Args:
-            id (str): Unique identifier of the 'Term' object. Defaults to 'None'.
-            name (): The preferred name of the term associated with the given accession number..
-            accession (): Accession number of the term in the controlled vocabulary..
-            term_cv_reference (): Reference to the `CV.id` of a controlled vocabulary that has been defined for this dataset.. Defaults to None
-            value (): Value of the term, if applicable.. Defaults to None
-        """
-        params = {
-            "name": name,
-            "accession": accession,
-            "term_cv_reference": term_cv_reference,
-            "value": value,
-        }
-        if id is not None:
-            params["id"] = id
-        self.keywords.append(Term(**params))
-        return self.keywords[-1]
-
-    def add_to_topics(
-        self,
-        name: str,
-        accession: str,
-        term_cv_reference: Optional[str] = None,
-        value: Optional[Any] = None,
-        id: Optional[str] = None,
-    ) -> None:
-        """
-        This method adds an object of type 'Term' to attribute topics
-
-        Args:
-            id (str): Unique identifier of the 'Term' object. Defaults to 'None'.
-            name (): The preferred name of the term associated with the given accession number..
-            accession (): Accession number of the term in the controlled vocabulary..
-            term_cv_reference (): Reference to the `CV.id` of a controlled vocabulary that has been defined for this dataset.. Defaults to None
-            value (): Value of the term, if applicable.. Defaults to None
-        """
-        params = {
-            "name": name,
-            "accession": accession,
-            "term_cv_reference": term_cv_reference,
-            "value": value,
-        }
-        if id is not None:
-            params["id"] = id
-        self.topics.append(Term(**params))
-        return self.topics[-1]
-
-    def add_to_related_publications(
-        self,
-        type: PublicationTypes,
-        title: str,
-        authors: List[Person] = ListPlus(),
-        year: Optional[int] = None,
-        doi: Optional[AnyUrl] = None,
-        id: Optional[str] = None,
-    ) -> None:
-        """
-        This method adds an object of type 'Publication' to attribute related_publications
-
-        Args:
-            id (str): Unique identifier of the 'Publication' object. Defaults to 'None'.
-            type (): Nature of the publication..
-            title (): Title of the publication..
-            authors (): Authors of the publication.. Defaults to ListPlus()
-            year (): Year of publication.. Defaults to None
-            doi (): The DOI pointing to the publication.. Defaults to None
-        """
-        params = {
-            "type": type,
-            "title": title,
-            "authors": authors,
-            "year": year,
-            "doi": doi,
-        }
-        if id is not None:
-            params["id"] = id
-        self.related_publications.append(Publication(**params))
-        return self.related_publications[-1]
diff --git a/nmrpy/datamodel/core/complexdatapoint.py b/nmrpy/datamodel/core/complexdatapoint.py
deleted file mode 100644
index 44ce1c2..0000000
--- a/nmrpy/datamodel/core/complexdatapoint.py
+++ /dev/null
@@ -1,32 +0,0 @@
-import sdRDM
-
-from typing import Optional
-from pydantic import Field
-from sdRDM.base.utils import forge_signature, IDGenerator
-
-
-@forge_signature
-class ComplexDataPoint(sdRDM.DataModel):
-    """Container for a complex number from the Free Induction Decay."""
-
-    id: Optional[str] = Field(
-        description="Unique identifier of the given object.",
-        default_factory=IDGenerator("complexdatapointINDEX"),
-        xml="@id",
-    )
-
-    real_part: Optional[float] = Field(
-        default=None,
-        description=(
-            "Real part of the complex number. Equivalent to `z.real` with `z` being a"
-            " `complex` number in Python."
-        ),
-    )
-
-    imaginary_part: Optional[float] = Field(
-        default=None,
-        description=(
-            "Imaginary part of the complex number. Equivalent to `z.imag` with `z`"
-            " being a `complex` number in Python."
-        ),
-    )
diff --git a/nmrpy/datamodel/core/cv.py b/nmrpy/datamodel/core/cv.py
index ccc6ca5..e7e070a 100644
--- a/nmrpy/datamodel/core/cv.py
+++ b/nmrpy/datamodel/core/cv.py
@@ -1,9 +1,11 @@
 import sdRDM
 
 from typing import Optional
-from pydantic import AnyUrl, Field, PrivateAttr
+from pydantic import Field
 from sdRDM.base.utils import forge_signature, IDGenerator
 
+from pydantic import AnyUrl
+
 
 @forge_signature
 class CV(sdRDM.DataModel):
@@ -29,7 +31,3 @@ class CV(sdRDM.DataModel):
         ...,
         description="URL pointing to the CV used.",
     )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
diff --git a/nmrpy/datamodel/core/datatypes.py b/nmrpy/datamodel/core/datatypes.py
deleted file mode 100644
index 92b2754..0000000
--- a/nmrpy/datamodel/core/datatypes.py
+++ /dev/null
@@ -1,10 +0,0 @@
-from enum import Enum
-
-
-class DataTypes(Enum):
-    CONCENTRATION = "conc"
-    ABSORPTION = "abs"
-    FEED = "feed"
-    BIOMASS = "biomass"
-    CONVERSION = "conversion"
-    PEAK_AREA = "peak-area"
diff --git a/nmrpy/datamodel/core/experiment.py b/nmrpy/datamodel/core/experiment.py
index d698bcf..e379b4f 100644
--- a/nmrpy/datamodel/core/experiment.py
+++ b/nmrpy/datamodel/core/experiment.py
@@ -1,14 +1,16 @@
 import sdRDM
 
 from typing import Optional, Union, List
-from pydantic import Field, PrivateAttr
+from pydantic import Field
 from sdRDM.base.listplus import ListPlus
 from sdRDM.base.utils import forge_signature, IDGenerator
+
+
 from .fidobject import FIDObject
 from .processingsteps import ProcessingSteps
-from .identity import Identity
 from .fidarray import FIDArray
 from .parameters import Parameters
+from .identity import Identity
 
 
 @forge_signature
@@ -38,10 +40,6 @@ class Experiment(sdRDM.DataModel):
         default=None,
         description="Multiple NMR spectra to be processed together.",
     )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
 
     def add_to_fid(
         self,
@@ -63,6 +61,7 @@ def add_to_fid(
             processing_steps (): Contains the processing steps performed, as well as the parameters used for them.. Defaults to None
             peak_identities (): Container holding and mapping integrals resulting from peaks and their ranges to EnzymeML species.. Defaults to ListPlus()
         """
+
         params = {
             "raw_data": raw_data,
             "processed_data": processed_data,
@@ -70,7 +69,10 @@ def add_to_fid(
             "processing_steps": processing_steps,
             "peak_identities": peak_identities,
         }
+
         if id is not None:
             params["id"] = id
+
         self.fid.append(FIDObject(**params))
+
         return self.fid[-1]
diff --git a/nmrpy/datamodel/core/fidarray.py b/nmrpy/datamodel/core/fidarray.py
index fae2599..1400e9c 100644
--- a/nmrpy/datamodel/core/fidarray.py
+++ b/nmrpy/datamodel/core/fidarray.py
@@ -1,7 +1,7 @@
 import sdRDM
 
 from typing import List, Optional
-from pydantic import Field, PrivateAttr
+from pydantic import Field
 from sdRDM.base.listplus import ListPlus
 from sdRDM.base.utils import forge_signature, IDGenerator
 
@@ -21,7 +21,3 @@ class FIDArray(sdRDM.DataModel):
         multiple=True,
         default_factory=ListPlus,
     )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
diff --git a/nmrpy/datamodel/core/fidobject.py b/nmrpy/datamodel/core/fidobject.py
index 513846b..61e4f00 100644
--- a/nmrpy/datamodel/core/fidobject.py
+++ b/nmrpy/datamodel/core/fidobject.py
@@ -1,12 +1,15 @@
 import sdRDM
 
 from typing import Optional, Union, List
-from pydantic import Field, PrivateAttr
+from pydantic import Field
 from sdRDM.base.listplus import ListPlus
 from sdRDM.base.utils import forge_signature, IDGenerator
+
+
 from .processingsteps import ProcessingSteps
-from .identity import Identity, AssociatedRanges
 from .parameters import Parameters
+from .identity import Identity
+from .identity import AssociatedRanges
 
 
 @forge_signature
@@ -35,16 +38,16 @@ class FIDObject(sdRDM.DataModel):
     )
 
     nmr_parameters: Optional[Parameters] = Field(
-        default=Parameters(),
         description="Contains commonly-used NMR parameters.",
+        default_factory=Parameters,
     )
 
     processing_steps: Optional[ProcessingSteps] = Field(
-        default=ProcessingSteps(),
         description=(
             "Contains the processing steps performed, as well as the parameters used"
             " for them."
         ),
+        default_factory=ProcessingSteps,
     )
 
     peak_identities: List[Identity] = Field(
@@ -55,10 +58,6 @@ class FIDObject(sdRDM.DataModel):
         default_factory=ListPlus,
         multiple=True,
     )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
 
     def add_to_peak_identities(
         self,
@@ -80,6 +79,7 @@ def add_to_peak_identities(
             associated_ranges (): Sets of ranges belonging to the given peaks. Defaults to ListPlus()
             associated_integrals (): Integrals resulting from the given peaks and ranges of a species. Defaults to ListPlus()
         """
+
         params = {
             "name": name,
             "species_id": species_id,
@@ -87,7 +87,10 @@ def add_to_peak_identities(
             "associated_ranges": associated_ranges,
             "associated_integrals": associated_integrals,
         }
+
         if id is not None:
             params["id"] = id
+
         self.peak_identities.append(Identity(**params))
+
         return self.peak_identities[-1]
diff --git a/nmrpy/datamodel/core/identifiertypes.py b/nmrpy/datamodel/core/identifiertypes.py
deleted file mode 100644
index f4bf8fe..0000000
--- a/nmrpy/datamodel/core/identifiertypes.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from enum import Enum
-
-
-class IdentifierTypes(Enum):
-    ORCID = "ORCID"
diff --git a/nmrpy/datamodel/core/identity.py b/nmrpy/datamodel/core/identity.py
index 3f28d1a..17c838b 100644
--- a/nmrpy/datamodel/core/identity.py
+++ b/nmrpy/datamodel/core/identity.py
@@ -1,7 +1,7 @@
 import sdRDM
 
 from typing import List, Optional
-from pydantic import Field, PrivateAttr
+from pydantic import Field
 from sdRDM.base.listplus import ListPlus
 from sdRDM.base.utils import forge_signature, IDGenerator
 
@@ -15,12 +15,10 @@ class AssociatedRanges(sdRDM.DataModel):
         default_factory=IDGenerator("associatedrangesINDEX"),
         xml="@id",
     )
+
     start: Optional[float] = Field()
+
     end: Optional[float] = Field()
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
 
 
 @forge_signature
@@ -60,10 +58,6 @@ class Identity(sdRDM.DataModel):
         default_factory=ListPlus,
         multiple=True,
     )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
 
     def add_to_associated_ranges(
         self,
@@ -79,8 +73,15 @@ def add_to_associated_ranges(
             start (): . Defaults to None
             end (): . Defaults to None
         """
-        params = {"start": start, "end": end}
+
+        params = {
+            "start": start,
+            "end": end,
+        }
+
         if id is not None:
             params["id"] = id
+
         self.associated_ranges.append(AssociatedRanges(**params))
+
         return self.associated_ranges[-1]
diff --git a/nmrpy/datamodel/core/nmrpy.py b/nmrpy/datamodel/core/nmrpy.py
index 9f68800..ab19951 100644
--- a/nmrpy/datamodel/core/nmrpy.py
+++ b/nmrpy/datamodel/core/nmrpy.py
@@ -1,10 +1,11 @@
 import sdRDM
 
 from typing import Optional
-from pydantic import Field, PrivateAttr
+from pydantic import Field
 from sdRDM.base.utils import forge_signature, IDGenerator
+
 from datetime import datetime as Datetime
-from .citation import Citation
+
 from .experiment import Experiment
 
 
@@ -32,15 +33,3 @@ class NMRpy(sdRDM.DataModel):
         default=None,
         description="List of experiments associated with this dataset.",
     )
-
-    citation: Optional[Citation] = Field(
-        default=Citation(),
-        description=(
-            "Relevant information regarding the publication and citation of this"
-            " dataset."
-        ),
-    )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
diff --git a/nmrpy/datamodel/core/parameters.py b/nmrpy/datamodel/core/parameters.py
index f2983ef..66f0c37 100644
--- a/nmrpy/datamodel/core/parameters.py
+++ b/nmrpy/datamodel/core/parameters.py
@@ -1,7 +1,7 @@
 import sdRDM
 
 from typing import List, Optional
-from pydantic import Field, PrivateAttr
+from pydantic import Field
 from sdRDM.base.listplus import ListPlus
 from sdRDM.base.utils import forge_signature, IDGenerator
 
@@ -67,7 +67,3 @@ class Parameters(sdRDM.DataModel):
         default=None,
         description="sw_left",
     )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
diff --git a/nmrpy/datamodel/core/person.py b/nmrpy/datamodel/core/person.py
deleted file mode 100644
index 0fc6d07..0000000
--- a/nmrpy/datamodel/core/person.py
+++ /dev/null
@@ -1,58 +0,0 @@
-import sdRDM
-
-from typing import List, Optional
-from pydantic import Field, PrivateAttr
-from sdRDM.base.listplus import ListPlus
-from sdRDM.base.utils import forge_signature, IDGenerator
-from .identifiertypes import IdentifierTypes
-
-
-@forge_signature
-class Person(sdRDM.DataModel):
-    """Container for information regarding a person that worked on an experiment."""
-
-    id: Optional[str] = Field(
-        description="Unique identifier of the given object.",
-        default_factory=IDGenerator("personINDEX"),
-        xml="@id",
-    )
-
-    last_name: str = Field(
-        ...,
-        description="Family name of the person.",
-    )
-
-    first_name: str = Field(
-        ...,
-        description="Given name of the person.",
-    )
-
-    middle_names: List[str] = Field(
-        description="List of middle names of the person.",
-        default_factory=ListPlus,
-        multiple=True,
-    )
-
-    affiliation: Optional[str] = Field(
-        default=None,
-        description="Institution the Person belongs to.",
-    )
-
-    email: Optional[str] = Field(
-        default=None,
-        description="Email address of the person.",
-    )
-
-    identifier_type: Optional[IdentifierTypes] = Field(
-        default=None,
-        description="Recognized identifier for the person.",
-    )
-
-    identifier_value: Optional[str] = Field(
-        default=None,
-        description="Value of the identifier for the person.",
-    )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
diff --git a/nmrpy/datamodel/core/processingsteps.py b/nmrpy/datamodel/core/processingsteps.py
index 8fdea85..e4c8830 100644
--- a/nmrpy/datamodel/core/processingsteps.py
+++ b/nmrpy/datamodel/core/processingsteps.py
@@ -1,7 +1,7 @@
 import sdRDM
 
 from typing import Optional
-from pydantic import Field, PrivateAttr
+from pydantic import Field
 from sdRDM.base.utils import forge_signature, IDGenerator
 
 
@@ -79,7 +79,3 @@ class ProcessingSteps(sdRDM.DataModel):
         default=False,
         description="Whether or not Baseline correction was performed.",
     )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
diff --git a/nmrpy/datamodel/core/protein.py b/nmrpy/datamodel/core/protein.py
deleted file mode 100644
index efcc389..0000000
--- a/nmrpy/datamodel/core/protein.py
+++ /dev/null
@@ -1,57 +0,0 @@
-import sdRDM
-
-from typing import Optional
-from pydantic import Field
-from sdRDM.base.utils import forge_signature, IDGenerator
-
-
-from .sboterm import SBOTerm
-
-
-@forge_signature
-class Protein(sdRDM.DataModel):
-    """This objects describes the proteins that were used or produced in the course of the experiment."""
-
-    id: Optional[str] = Field(
-        description="Unique identifier of the given object.",
-        default_factory=IDGenerator("proteinINDEX"),
-        xml="@id",
-    )
-
-    sequence: str = Field(
-        ...,
-        description="Amino acid sequence of the protein",
-        template_alias="Sequence",
-    )
-
-    ecnumber: Optional[str] = Field(
-        default=None,
-        description="EC number of the protein.",
-        regex="(\d+.)(\d+.)(\d+.)(\d+)",
-        template_alias="EC Number",
-    )
-
-    organism: Optional[str] = Field(
-        default=None,
-        description="Organism the protein was expressed in.",
-        template_alias="Source organism",
-    )
-
-    organism_tax_id: Optional[str] = Field(
-        default=None,
-        description="Taxonomy identifier of the expression host.",
-    )
-
-    uniprotid: Optional[str] = Field(
-        default=None,
-        description=(
-            "Unique identifier referencing a protein entry at UniProt. Use this"
-            " identifier to initialize the object from the UniProt database."
-        ),
-        template_alias="UniProt ID",
-    )
-
-    ontology: SBOTerm = Field(
-        description="None",
-        default=SBOTerm.CATALYST,
-    )
diff --git a/nmrpy/datamodel/core/publication.py b/nmrpy/datamodel/core/publication.py
deleted file mode 100644
index f3f8e50..0000000
--- a/nmrpy/datamodel/core/publication.py
+++ /dev/null
@@ -1,88 +0,0 @@
-import sdRDM
-
-from typing import List, Optional
-from pydantic import AnyUrl, Field, PrivateAttr
-from sdRDM.base.listplus import ListPlus
-from sdRDM.base.utils import forge_signature, IDGenerator
-from .identifiertypes import IdentifierTypes
-from .person import Person
-from .publicationtypes import PublicationTypes
-
-
-@forge_signature
-class Publication(sdRDM.DataModel):
-    """Container for citation information of a relevant publication."""
-
-    id: Optional[str] = Field(
-        description="Unique identifier of the given object.",
-        default_factory=IDGenerator("publicationINDEX"),
-        xml="@id",
-    )
-
-    type: PublicationTypes = Field(
-        ...,
-        description="Nature of the publication.",
-    )
-
-    title: str = Field(
-        ...,
-        description="Title of the publication.",
-    )
-
-    authors: List[Person] = Field(
-        description="Authors of the publication.",
-        multiple=True,
-        default_factory=ListPlus,
-    )
-
-    year: Optional[int] = Field(
-        default=None,
-        description="Year of publication.",
-    )
-
-    doi: Optional[AnyUrl] = Field(
-        default=None,
-        description="The DOI pointing to the publication.",
-    )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
-
-    def add_to_authors(
-        self,
-        last_name: str,
-        first_name: str,
-        middle_names: List[str] = ListPlus(),
-        affiliation: Optional[str] = None,
-        email: Optional[str] = None,
-        identifier_type: Optional[IdentifierTypes] = None,
-        identifier_value: Optional[str] = None,
-        id: Optional[str] = None,
-    ) -> None:
-        """
-        This method adds an object of type 'Person' to attribute authors
-
-        Args:
-            id (str): Unique identifier of the 'Person' object. Defaults to 'None'.
-            last_name (): Family name of the person..
-            first_name (): Given name of the person..
-            middle_names (): List of middle names of the person.. Defaults to ListPlus()
-            affiliation (): Institution the Person belongs to.. Defaults to None
-            email (): Email address of the person.. Defaults to None
-            identifier_type (): Recognized identifier for the person.. Defaults to None
-            identifier_value (): Value of the identifier for the person.. Defaults to None
-        """
-        params = {
-            "last_name": last_name,
-            "first_name": first_name,
-            "middle_names": middle_names,
-            "affiliation": affiliation,
-            "email": email,
-            "identifier_type": identifier_type,
-            "identifier_value": identifier_value,
-        }
-        if id is not None:
-            params["id"] = id
-        self.authors.append(Person(**params))
-        return self.authors[-1]
diff --git a/nmrpy/datamodel/core/publicationtypes.py b/nmrpy/datamodel/core/publicationtypes.py
deleted file mode 100644
index f5974ef..0000000
--- a/nmrpy/datamodel/core/publicationtypes.py
+++ /dev/null
@@ -1,5 +0,0 @@
-from enum import Enum
-
-
-class PublicationTypes(Enum):
-    ARTICLE = "Journal article"
diff --git a/nmrpy/datamodel/core/reactant.py b/nmrpy/datamodel/core/reactant.py
deleted file mode 100644
index faf65c1..0000000
--- a/nmrpy/datamodel/core/reactant.py
+++ /dev/null
@@ -1,49 +0,0 @@
-import sdRDM
-
-from typing import Optional
-from pydantic import Field
-from sdRDM.base.utils import forge_signature, IDGenerator
-
-
-from .sboterm import SBOTerm
-
-
-@forge_signature
-class Reactant(sdRDM.DataModel):
-    """This objects describes the reactants that were used or produced in the course of the experiment."""
-
-    id: Optional[str] = Field(
-        description="Unique identifier of the given object.",
-        default_factory=IDGenerator("reactantINDEX"),
-        xml="@id",
-    )
-
-    smiles: Optional[str] = Field(
-        default=None,
-        description=(
-            "Simplified Molecular Input Line Entry System (SMILES) encoding of the"
-            " reactant."
-        ),
-        template_alias="SMILES",
-    )
-
-    inchi: Optional[str] = Field(
-        default=None,
-        description=(
-            "International Chemical Identifier (InChI) encoding of the reactant."
-        ),
-        template_alias="InCHI",
-    )
-
-    chebi_id: Optional[str] = Field(
-        default=None,
-        description=(
-            "Unique identifier of the CHEBI database. Use this identifier to initialize"
-            " the object from the CHEBI database."
-        ),
-    )
-
-    ontology: SBOTerm = Field(
-        description="None",
-        default=SBOTerm.SMALL_MOLECULE,
-    )
diff --git a/nmrpy/datamodel/core/sboterm.py b/nmrpy/datamodel/core/sboterm.py
deleted file mode 100644
index 74d2eb6..0000000
--- a/nmrpy/datamodel/core/sboterm.py
+++ /dev/null
@@ -1,35 +0,0 @@
-from enum import Enum
-
-
-class SBOTerm(Enum):
-    BIOCHEMICAL_REACTION = "SBO:0000176"
-    ACID_BASE_REACTION = "SBO:0000208"
-    CONFORMATIONAL_TRANSITION = "SBO:0000181"
-    CONVERSION = "SBO:0000182"
-    DEGRADATION = "SBO:0000179"
-    DISSOCIATION = "SBO:0000180"
-    IONISATION = "SBO:0000209"
-    ISOMERISATION = "SBO:0000377"
-    NON_COVALENT_BINDING = "SBO:0000177"
-    REDOX_REACTION = "SBO:0000200"
-    SPONTANEOUS_REACTION = "SBO:0000672"
-    PROTEIN = "SBO:0000252"
-    GENE = "SBO:0000251"
-    SMALL_MOLECULE = "SBO:0000247"
-    ION = "SBO:0000327"
-    RADICAL = "SBO:0000328"
-    INTERACTOR = "SBO:0000336"
-    SUBSTRATE = "SBO:0000015"
-    PRODUCT = "SBO:0000011"
-    CATALYST = "SBO:0000013"
-    INHIBITOR = "SBO:0000020"
-    ESSENTIAL_ACTIVATOR = "SBO:0000461"
-    NON_ESSENTIAL_ACTIVATOR = "SBO:0000462"
-    POTENTIATOR = "SBO:0000021"
-    MACROMOLECULAR_COMPLEX = "SBO:0000296"
-    PROTEIN_COMPLEX = "SBO:0000297"
-    DIMER = "SBO:0000607"
-    MICHAELIS_MENTEN = "SBO:0000028"
-    K_CAT = "SBO:0000025"
-    K_M = "SBO:0000027"
-    V_MAX = "SBO:0000186"
diff --git a/nmrpy/datamodel/core/subjects.py b/nmrpy/datamodel/core/subjects.py
deleted file mode 100644
index d343f01..0000000
--- a/nmrpy/datamodel/core/subjects.py
+++ /dev/null
@@ -1,8 +0,0 @@
-from enum import Enum
-
-
-class Subjects(Enum):
-    BIOLOGY = "Biology"
-    CHEMISTRY = "Chemistry"
-    IT = "Computer and Information Science"
-    PHYSICS = "Physics"
diff --git a/nmrpy/datamodel/core/term.py b/nmrpy/datamodel/core/term.py
index eabbad0..82c67e8 100644
--- a/nmrpy/datamodel/core/term.py
+++ b/nmrpy/datamodel/core/term.py
@@ -1,9 +1,11 @@
 import sdRDM
 
-from typing import Any, Optional
-from pydantic import Field, PrivateAttr
+from typing import Optional
+from pydantic import Field
 from sdRDM.base.utils import forge_signature, IDGenerator
 
+from typing import Any
+
 
 @forge_signature
 class Term(sdRDM.DataModel):
@@ -39,7 +41,3 @@ class Term(sdRDM.DataModel):
         default=None,
         description="Value of the term, if applicable.",
     )
-    __repo__: Optional[str] = PrivateAttr(default="https://github.com/NMRPy/nmrpy")
-    __commit__: Optional[str] = PrivateAttr(
-        default="dec2cda6676f8d04070715fe079ed786515ea918"
-    )
diff --git a/nmrpy/datamodel/core/vessel.py b/nmrpy/datamodel/core/vessel.py
deleted file mode 100644
index 5dc6fb5..0000000
--- a/nmrpy/datamodel/core/vessel.py
+++ /dev/null
@@ -1,52 +0,0 @@
-import sdRDM
-
-from typing import Optional
-from pydantic import Field
-from sdRDM.base.utils import forge_signature, IDGenerator
-
-from pydantic import StrictBool
-from pydantic import PositiveFloat
-
-
-@forge_signature
-class Vessel(sdRDM.DataModel):
-    """This object describes vessels in which the experiment has been carried out. These can include any type of vessel used in biocatalytic experiments."""
-
-    id: Optional[str] = Field(
-        description="Unique identifier of the given object.",
-        default_factory=IDGenerator("vesselINDEX"),
-        xml="@id",
-    )
-
-    name: str = Field(
-        ...,
-        description="Name of the used vessel.",
-        template_alias="Name",
-    )
-
-    volume: PositiveFloat = Field(
-        ...,
-        description="Volumetric value of the vessel.",
-        template_alias="Volume value",
-    )
-
-    unit: str = Field(
-        ...,
-        description="Volumetric unit of the vessel.",
-        template_alias="Volume unit",
-    )
-
-    constant: StrictBool = Field(
-        description="Whether the volume of the vessel is constant or not.",
-        default=True,
-    )
-
-    uri: Optional[str] = Field(
-        default=None,
-        description="URI of the vessel.",
-    )
-
-    creator_id: Optional[str] = Field(
-        default=None,
-        description="Unique identifier of the author.",
-    )
diff --git a/nmrpy/datamodel/schemes/datamodel_schema.md b/nmrpy/datamodel/schemes/datamodel_schema.md
index 85785fa..0cf4664 100644
--- a/nmrpy/datamodel/schemes/datamodel_schema.md
+++ b/nmrpy/datamodel/schemes/datamodel_schema.md
@@ -1,25 +1,16 @@
 ```mermaid
 classDiagram
     NMRpy *-- Experiment
-    NMRpy *-- Citation
     Experiment *-- FIDObject
     Experiment *-- FIDArray
     FIDObject *-- Parameters
     FIDObject *-- ProcessingSteps
     FIDObject *-- Identity
-    Citation *-- Subjects
-    Citation *-- Person
-    Citation *-- Publication
-    Citation *-- Term
-    Person *-- IdentifierTypes
-    Publication *-- PublicationTypes
-    Publication *-- Person
     
     class NMRpy {
         +datetime datetime_created*
         +datetime datetime_modified
         +Experiment experiment
-        +Citation citation
     }
     
     class Experiment {
@@ -77,38 +68,6 @@ classDiagram
         +string[0..*] fids*
     }
     
-    class Citation {
-        +string title
-        +URL doi
-        +string description
-        +Person[0..*] authors
-        +Subjects[0..*] subjects
-        +Term[0..*] keywords
-        +Term[0..*] topics
-        +Publication[0..*] related_publications
-        +string notes
-        +string[0..*] funding
-        +string license
-    }
-    
-    class Person {
-        +string last_name*
-        +string first_name*
-        +string[0..*] middle_names
-        +string affiliation
-        +string email
-        +IdentifierTypes identifier_type
-        +string identifier_value
-    }
-    
-    class Publication {
-        +PublicationTypes type*
-        +string title*
-        +Person[0..*] authors*
-        +integer year
-        +URL doi
-    }
-    
     class CV {
         +string vocabulary*
         +string version*
@@ -129,22 +88,4 @@ classDiagram
         +NONE
     }
     
-    class Subjects {
-        << Enumeration >>
-        +BIOLOGY
-        +CHEMISTRY
-        +IT
-        +PHYSICS
-    }
-    
-    class PublicationTypes {
-        << Enumeration >>
-        +ARTICLE
-    }
-    
-    class IdentifierTypes {
-        << Enumeration >>
-        +ORCID
-    }
-    
 ```
\ No newline at end of file
diff --git a/nmrpy/plotting.py b/nmrpy/plotting.py
index bd470b3..f328381 100644
--- a/nmrpy/plotting.py
+++ b/nmrpy/plotting.py
@@ -19,11 +19,13 @@
     Label,
     Button,
     Combobox,
+    Text,
+    HTML,
 )
 from IPython.display import display
 import asyncio
 
-from .utils import get_species_from_enzymeml
+from .utils import get_species_from_enzymeml, get_ordered_list_of_species_names
 
 
 class Plot:
@@ -185,7 +187,9 @@ def _plot_deconv(
             ax.text(
                 ppm[numpy.argmax(peak)],
                 label_pad + peak.max(),
-                str(n),
+                get_ordered_list_of_species_names(fid)[n]
+                if fid.fid_object.peak_identities
+                else str(n),
                 ha="center",
             )
         ax.invert_xaxis()
@@ -1458,6 +1462,7 @@ def on_save_button_click(b):
                                 }
                             ],
                         )
+            self.fid.identities = get_ordered_list_of_species_names(self.fid)
             self.fid._flags["assigned"] = True
             reset_button.disabled = False
 
@@ -1480,6 +1485,7 @@ def on_reset_button_click(b):
                 peak_dropdown.options = self.available_peaks
                 peak_dropdown.disabled = False
                 save_button.disabled = False
+                self.fid.identities = None
                 self.fid._flags["assigned"] = False
                 reset_button.disabled = True
 
@@ -1657,6 +1663,7 @@ def on_save_button_click(b):
                                     }
                                 ],
                             )
+                        fid.identities = get_ordered_list_of_species_names(fid)
             reset_button.disabled = False
 
         # Attach the function to the save button's click event
@@ -1671,6 +1678,7 @@ def on_reset_button_click(b):
                 print("\nCleared selections!")
                 for fid in self.fids:
                     fid.fid_object.peak_identities = []
+                    fid.identities = None
                 self.selected_values = {}
                 # Refill the list of available peaks as before,
                 # re-enable the peak dropdown, and disable the reset
@@ -2197,5 +2205,113 @@ def assign(self):
         plt.close(self.span_selector.fig)
 
 
+class ConcentrationCalculator:
+    def __init__(self, fid_array, integrals):
+        self.fid_array = fid_array
+        self.integrals = integrals
+        self.fids = fid_array.get_fids()
+        self.available_species = get_ordered_list_of_species_names(
+            self.fid_array.get_fid("fid00")
+        )
+        self.equation = ""
+
+        # Create the label widget for the title
+        title_label = Label(
+            value="[WORK IN PROGRESS]    Calculate concentrations from peak integrals for all FIDs    [WORK IN PROGRESS]"
+        )
+
+        # Create the dropdown widget for the internal standard
+        standard_dropdown = Dropdown(
+            options=self.available_species,
+            description="Select the internal standard:",
+            layout={"width": "max-content"},
+            style={"description_width": "initial"},
+        )
+
+        # Create a text input widget for the concentration equation
+        concentration_equation = Text(
+            value="",
+            placeholder="Enter the equation for the concentration here",
+            description="Concentration equation:",
+            layout={"width": "auto"},
+            style={
+                "description_width": "initial",
+            },
+        )
+
+        # Create an HTML widget to display a legend for the concentration equation
+        legend_html = HTML(
+            value="'c_s': Concentration of species<br>'c_n': Concentration of internal standard<br>'x_s': Peak integral of species<br>'x_n': Peak integral of internal standard<br>Example: c_s = c_n * x_s / x_n",
+            description="Legend:",
+        )
+
+        # Create a button to calculate the concentrations
+        calculate_button = Button(
+            description="Calculate concentrations",
+            icon="calculator",
+            layout={"width": "max-content"},
+            disabled=True,
+        )
+
+        # Create an output widget to display the calculation progress
+        output = Output()
+
+        # Define a method to handle the text input widget's change event
+        def on_text_change(event):
+            if event["type"] == "change" and event["name"] == "value":
+                calculate_button.disabled = False
+
+        # Attach the method to the text input widget's change event
+        concentration_equation.observe(on_text_change)
+
+        # Define a method to handle the calculate button's click event
+        def on_calculate_button_click(b):
+            with output:
+                output.clear_output(wait=True)
+                # Fetch the values from the standard dropdown and the
+                # text widget and add them to a dictionary with species as
+                # keys
+                print("\nCalculating concentrations...")
+                if (
+                    not concentration_equation.value.replace(" ", "")
+                    == "c_s=c_n*x_s/x_n"
+                ):
+                    raise NotImplementedError(
+                        "Only the example formula is currently supported."
+                    )
+                else:
+                    # TODO: Currently hard-coded for the example data
+                    standard_index = self.available_species.index(
+                        standard_dropdown.value
+                    )
+                    self.fid_array.concentrations = {
+                        species: 5
+                        * concentration
+                        / self.integrals[standard_index].mean()
+                        for species, concentration in zip(
+                            self.available_species, self.integrals
+                        )
+                    }
+                print(f"Done! Get concentrations with `FidArray.concentrations`.")
+
+        # Attach the function to the calculate button's click event
+        calculate_button.on_click(on_calculate_button_click)
+
+        # Create the container
+        container = VBox(
+            [
+                title_label,
+                standard_dropdown,
+                concentration_equation,
+                legend_html,
+                calculate_button,
+                output,
+            ]
+        )
+
+        # Display the container
+        display(container)
+
+
 if __name__ == "__main__":
     pass
diff --git a/nmrpy/utils.py b/nmrpy/utils.py
index 5732fb1..8d206d9 100644
--- a/nmrpy/utils.py
+++ b/nmrpy/utils.py
@@ -26,3 +26,59 @@ def get_species_from_enzymeml(enzymeml_document: DataModel) -> list:
     for reactant in enzymeml_document.reactants:
         available_species.append(reactant)
     return available_species
+
+
+def get_ordered_list_of_species_names(fid: "Fid") -> list:
+    """Iterate over the identites in a given FID object and extract a
+    list of species names ordered by peak index, multiple occurences
+    thus allowed.
+
+    Args:
+        fid (Fid): The FID object from which to get the species names.
+
+    Returns:
+        list: List of species names in desecending order by peak index.
+    """
+    list_of_tuples = []
+    # Iterate over the identies and then over their associated peaks of
+    # a given FID object and append a tuple of the identity's name and
+    # corresponding peak (one tuple per peak) to a list of tuples.
+    for identity in fid.fid_object.peak_identities:
+        for peak in identity.associated_peaks:
+            list_of_tuples.append((identity.name, peak))
+    # Use the `sorted` function with a custom key to sort the list of
+    # tuples by the second element of each tuple (the peak) from highest
+    # value to lowest (reverse=True).
+    list_of_tuples = sorted(list_of_tuples, key=lambda x: x[1], reverse=True)
+    # Create and return an ordered list of only the species names from
+    # the sorted list of tuples.
+    ordered_list_of_species_names = [t[0] for t in list_of_tuples]
+    return ordered_list_of_species_names
+
+
+def create_enzymeml(fid_array: "FidArray", enzymeml_document: DataModel) -> DataModel:
+    # Specify EnzymeML version
+    URL = "https://github.com/EnzymeML/enzymeml-specifications.git"
+    COMMIT = "5e5f05b9dc76134305b8f9cef65271e35563ac76"
+
+    EnzymeML = DataModel.from_git(URL, COMMIT)
+    SBOTerm = EnzymeML.enums.SBOTerm
+    DataTypes = EnzymeML.enums.DataTypes
+
+    measurement = EnzymeML.Measurement(
+        name=fid_array.data_model.experiment.name,
+        temperature=enzymeml_document.reactions[0].temperature,
+        temperature_unit=enzymeml_document.reactions[0].temperature_unit,
+        ph=enzymeml_document.reactions[0].ph,
+        global_time=fid_array.t.tolist(),
+        global_time_unit="min",
+    )
+
+    enzymeml_document.measurements.append(measurement)
+
+    return enzymeml_document
+
+    # for species, concentrations in fid_array.concentrations.items():
+    #     new_species = EnzymeML.MeasurementData(
+    #         init_conc=enzymeml_document.reactants
+    #     )
diff --git a/specifications/nmrpy.md b/specifications/nmrpy.md
index 0adcf22..d433e21 100644
--- a/specifications/nmrpy.md
+++ b/specifications/nmrpy.md
@@ -19,9 +19,6 @@ Root element of the NMRpy data model.
 - experiment
   - Type: [Experiment](#experiment)
   - Description: List of experiments associated with this dataset.
-- citation
-  - Type: [Citation](#citation)
-  - Description: Relevant information regarding the publication and citation of this dataset.
 
 
 ### Experiment
@@ -189,102 +186,6 @@ Container for processing of multiple spectra. Must reference the respective `FID
   - Multiple: True
 
 
-### Citation
-
-Container for various types of metadata primarily used in the publication and citation of the dataset.
-
-- title
-  - Type: string
-  - Description: Title the dataset should have when published.
-- doi
-  - Type: URL
-  - Description: DOI pointing to the published dataset
-- description
-  - Type: string
-  - Description: Description the dataset should have when published.
-- authors
-  - Type: [Person](#person)
-  - Description: List of authors for this dataset.
-  - Multiple: True
-- subjects
-  - Type: [Subjects](#subjects)
-  - Description: List of subjects this dataset belongs to.
-  - Multiple: True
-- keywords
-  - Type: [Term](#term)
-  - Description: List of CV-based keywords describing the dataset.
-  - Multiple: True
-- topics
-  - Type: [Term](#term)
-  - Description: List of CV-based topics the dataset addresses.
-  - Multiple: True
-- related_publications
-  - Type: [Publication](#publication)
-  - Description: List of publications relating to this dataset.
-  - Multiple: True
-- notes
-  - Type: string
-  - Description: Additional notes about the dataset.
-- funding
-  - Type: string
-  - Description: Funding information for this dataset.
-  - Multiple: True
-- license
-  - Type: string
-  - Description: License information for this dataset. Defaults to `CC BY 4.0`.
-  - Default: CC BY 4.0
-
-
-### Person
-
-Container for information regarding a person that worked on an experiment.
-
-- __last_name__
-  - Type: string
-  - Description: Family name of the person.
-- __first_name__
-  - Type: string
-  - Description: Given name of the person.
-- middle_names
-  - Type: string
-  - Description: List of middle names of the person.
-  - Multiple: True
-- affiliation
-  - Type: string
-  - Description: Institution the Person belongs to.
-- email
-  - Type: string
-  - Description: Email address of the person.
-- identifier_type
-  - Type: [IdentifierTypes](#identifiertypes)
-  - Description: Recognized identifier for the person.
-- identifier_value
-  - Type: string
-  - Description: Value of the identifier for the person.
-
-
-### Publication
-
-Container for citation information of a relevant publication.
-
-- __type__
-  - Type: [PublicationTypes](#publicationtypes)
-  - Description: Nature of the publication.
-- __title__
-  - Type: string
-  - Description: Title of the publication.
-- __authors__
-  - Type: [Person](#person)
-  - Description: Authors of the publication.
-  - Multiple: True
-- year
-  - Type: integer
-  - Description: Year of publication.  
-- doi
-  - Type: URL
-  - Description: The DOI pointing to the publication.
-
-
 ## Utility objects
 
 
@@ -334,33 +235,3 @@ VARIAN = "varian"
 BRUKER = "bruker"
 NONE = None
 ```
-
-
-### Subjects
-
-Enumeration containing common subjects (research fields) that implement NMR.
-
-```python
-BIOLOGY = "Biology"
-CHEMISTRY = "Chemistry"
-IT = "Computer and Information Science"
-PHYSICS = "Physics"
-```
-
-
-### PublicationTypes
-
-Enumeration containing accepted types of publication.
-
-```python
-ARTICLE = "Journal article"
-```
-
-
-### IdentifierTypes
-
-Enumeration containing recognized identifiers for persons.
-
-```python
-ORCID = "ORCID"
-```