AN IMPROVED ANHARMONIC POTENTIAL FOR CHF3

We have investigated the potential energy surface of CHF3 theoreticall y using standard quantum chemical methods. The harmonic force field wa s obtained by an MP2 calculation, while the cubic and quartic componen ts have been evaluated at the SCF level in Cartesian coordinates. Fina lly we scaled the geometry and the potential in symmetry coordinates t o reproduce the experimental ground state rotational constants, fundam entals, overtones, and quartic and sextic centrifugal distortion const ants of two isotopomers. (C) 1996 Academic Press, Inc.