_atom_site_anisotrop.U - definition does not match usage

[wojdyr]

Item _atom_site_anisotrop.U[1][1] and related items are
defined in the PDBx/mmCIF and mmCIF dictionaries in the same way as in the core CIF dictionary - as U_uvrs (U in the reciprocal space vectors basis).
In the wwPDB the actual values stored in these tags are U_cart (in the Cartesian basis) - similarly to the PDB ANISOU.

The symbols above are from paper by RWGK and Adams (2002).

In "Biomolecular Crystallography", page 641, B. Rupp uses symbol U_cif instead of U_uvrs, but he also states that mmCIF files use U_cif not U_cart.

[epeisach]

I will need to track down these references and confirm current usage.