VIBRATZ for normal-coordinate vibrational analysis (Windows 95/98/NT or PowerMac)

This program will do a complete normal-coordinate calculation on any molecule or crystal, using traditional valence force constants and/or Urey-Bradley force constants.

Input is: 1) the space group for crystals or polymers or the point group for molecules, selected from complete lists;  2) unit-cell parameters for crystals; 3) coordinates of the atoms, either a symmetry-unique set or all atoms; 4) specifications for force constants in terms of atom types (typically atomic numbers) and bond distance and angle limits.

The calculation is ultimately done in Cartesian coordinates, not internal coordinates, so there is no need to limit the number of force constants or to provide redundancy equations.  Force-constants specifications can be easily transferred between structures.  Forces may also be entered in the form of a Cartesian matrix, so that any (short-range) potential-energy function may be used.

Input data can be read from files with many crystallographic and molecular formats (see File Formats Supported).

Output is: 1) a complete list of frequencies of the fundamental vibrational modes (optical or kappa=0 modes in the case of crystals); 2) atomic motions in each mode; 3) potential-energy distribution; 4) plot of the structure with atomic motions; 5) synthetic infrared and Raman spectra.