A FLEXIBLE METHOD FOR CALCULATING EIGENVALUES AND EIGENVECTORS FOR THE INTERNAL ROTOR PROBLEM

摘要

The general utility of a discretized variable basis for the internal rotor eigenvalue problem. especially when coupled with an algebraic determinantal approach, is demonstrated. The computational routines are simple recursive ones and the incorporation of symmetry constraints is straightforward. The method is first applied to a model problem with C-2 upsilon symmetry and the results compared with the conventional functional basis approach. Generation of the different symmetry species in C-6 upsilon is illustrated by the internal rotation in toluene. After introducing splined potentials, which allow selected parts of the potential to be modified, the infrared spectrum of the torsional mode of propanal is discussed. (C) 1997 Academic Press. [References: 15]