THIS INFORMATION IS OBSOLETE AND IS PROVIDED ONLY FOR ITS HISTORICAL VALUE

by Alfonso Nino and Camelia Munoz-Caro, E. U. Informatica de Ciudad Real, Universidad de Castilla-La Mancha, Ronda de Calatrava 5, 13071 Ciudad Real, Spain

FITVIB is a program for refining kinetic and potential energy functions for several large amplitude vibrations. These functions are expressed as Fourier expansions on the anharmonic large amplitude coordinates^1,2. The program minimizes the sum of squares of the differences between calculated and experimental energy levels using a multidimensional Newton-like algorithm. For large amplitude vibrations the position of the energy levels depends on the kinetic and potential terms. Thus, all these terms are included in the minimization procedure. The program is especially useful for deriving accurate potential functions for torsional (internal rotation) motions. Thus, reliable values for the barriers to rotation and the equilibrium conformations can be obtained. The program is written in standard FORTRAN 77 and runs under the UNIX operating system.

_________ References:

1. A. Niñno, C. Munoz-Caro and D. C. Moule, J. Phys. Chem., 98, 1519 (1994). 2. C. Muñoz-Caro, A. Niño and D. C. Moule, Chem. Phys., in press.

Lines of Code: 2731 FORTRAN 77 (UNIX)