MOLCRYST is a package for studying the structure and dynamics of
molecular crystalls originally written by Andrei M. Tokmachev and Andrei L.
Tchougreeff and later significanlty improved by Anton V. Sinitskii who
successfully applied it to study of spin transitions in molecular crystals
of iron(II) complexes.
The optimal values of periods and angles determining the primitive cell and also the positions and orientations of molecules inside the primitive cell are calculated by the direct minimization of the energy modelled by atom-atom potentials scheme. The package allows to use the Buckingham or 6-12 potentials. Standard parameterization used is Universal Force Field (Rappe et al., JACS, 1993). The equilibrium geometrical structure of molecular crystal is used to calculate the phonon spectra for any value of the wave vector. The frequencies (in cm**-1) and eigenvectors of normal vibrations are printed. The package allows to calculate the vibrational part of the Helmholtz energy by means of scanning of the reciprocal space and also the total Helmholtz energy for intermolecular interactions in the molecular crystal. It is also possible the calculation of the sound velocities in the molecular crystal in the directions marked out.
Source: MOLCRYST, by Andrei M. Tokmachev and Andrei L. Tchougreeff.
Documentation: A short MOLCRYST reference is available on-line. More elaborated version is under construction.