Solids modeled by ab initio crystal field methods, part 22: The Fock matrix transformed supermolecule model and the structure determination of D-erythronic acid-3,4-carbonate

To eliminate the cutoff effects in the supermolecule model (SM), the Fock matrix transformed supermolecule model (FTSM) is developed. In this model a cyclization of the cluster is performed by means of transformations of elements of the Fock matrix, thereby restoring the translational symmetry. Besides this fundamental enhancement, significant CPU time savings are realized because, in this new procedure, not all Fock matrix elements need to be calculated. The method is applied in a study of the structure of D-erythronic acid-3,4-carbonate in the crystal phase, where the new model is compared to the supermolecule model as well as the XRD experiment. The results are found to be in good agreement with experimental data. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 2065–2072, 2004