This is a suite of molecular dynamics and interatomic force routines 
developed by D.W. Brenner, J.A. Harrison S.B. Sinnott and O. Shenderova. 
I have tried to make this code as modular as possible so that new  
subroutines can be added as they are developed. The code currently 
includes forces and energies for the newest version of the hydrocarbon 
potential, Tersoff's silicon-III and germanium potentials, Lennard-Jones 
interactions, and the Xu/Ho tight-binding parameterization for carbon. 
Embedded-atom potentials as well as other tight binding parameterizations 
will be added in the near future. 

The subdirectories are organized according to the files that they contain.  
The intention is that these files be kept in a safe place,  preferably with 
read only privilages. The subroutines and input files can be copied into 
the areas of individual users as needed, and the routines then customized.
This leaves the original source for other users. Also, with this structure 
access to rather large input files needed for the splines is made through 
include files (denoted by the suffix .inc) so that multiple copies of these
files do not need to be kept. README files in the subdirectories give 
specific information about those directories. 

The main routine is ./Subroutines/General/main.f. Source code for subroutines,
which are kept under the directory ./Subroutines, are appended to the end of
main.f with the include file subroutines.inc. If one wants to add a specialized 
routine, this is done by adding the name of the file containing the routine to 
the list in subroutines.inc. 

Parameters governing things such as the maximum number of atoms, the maximum 
number of steps, size of arrays for neighbor lists, etc. are determined by 
the include file parameters.inc which is stored in the directory ./Include. 
A brief description of what some of the parameters correspond to are in this file. 

Common blocks are added to the routines through the include file 
commons_files.inc which is stored in the directory ./Include.. This file is 
currently set up to use the commons in the subdirectory ./Commons. These can be 
customized by copying the appropriate common blocks into the user's area, 
making the changes, and then modifying commons_files.inc to include the new 
common block.

Each of the include files from ./Include as well as the desired subroutines 
from the directories under ./Subroutines should be copied into the user's
area and pathnames appropriately modified. 

The subdirectory `Execute' contains copies of files from the other 
directories that are required to run the basic code. 


README files in the other subdirectories specify what is in those directories. 

Execute: 

This contains copies from the other directories of all of the 
files needed to run the basic code. The main code which calls 
the other subroutines is `main.f'. There are very brief comments
in this file that specify what is done by each subroutine.

To compile the code 

f77 -o main.x main.f 

In addition, using the O3 level of optimization on my SGI speeds 
up execution of the code. 

Source code for the subroutines that are called in `main.f' 
are appended to the end of this file with the include file 
`subroutines.inc'.  If one wants to add a specialized routine, 
this is done by adding the name of the file containing the 
routine to the list in `subroutines.inc'.  

Parameters governing things such as the maximum number of 
atoms, the maximum number of steps, size of arrays for 
neighbor lists, etc. are determined by the include file 
`parameters.inc'. A brief description of what some of the 
parameters correspond to are in this file.  

Common blocks are added to the routines through the include 
file `commons_files.inc'. It is currently set up to use the 
commons in the subdirectory `Commons'. These can be customized
by copying the appropriated common blocks into the user's area,
making the changes, and then modifying `commons.inc' to 
include the new common block.