			15min:

AB INITIO POTENTIAL ENERGY SURFACE AND EIGENVALUES OF A² Delta

STATE OF ArCH.

ALEXEY L. KALEDIN, ANATOLY V. KOMISSAROV AND MICHAEL C. HEAVEN, Department of Chemistry, Emory University, Atlanta, GA 30322 .

\hspace3em Rotationally resolved spectra of A-X transition of ArCH/D van der Waals complex have been reported previously and 7 bands were tentatively assigned. In order to make more definite assignments high level ab initio calculations have been performed.

.5em

\hspace3em2-D interaction potential for CH(A)-Ar (with CH bond fixed at r_e=1.102Å for A² Delta ) was calculated with MRSDCI method including Davidson and counterpoise correction. The basis set was Dunning's correlation-consistent vqz with diffuse s and p orbitals.

.5em

\hspace3em The potential surface exhibits two minima, linear Ar...H-C and Ar...C-H whose respective well depths are 85 cm^-1 and 60 cm^-1. The potential anisotropy is dominated by dipole and quadrupole terms on CH. Bound ro-vibrational eigentates were calculated for various \textbfJ values and compared with experimental results.