Knowledge Bank

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. 2-D interaction potential for $CH(A)-Ar$ (with CH bond fixed at $rc=1.102\backslash AA$ 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. The potential surface exhibits two minima, linear $Ar\dots H-C$. and $Ar\dots C-H$ whose respective well depths are $85cm-1$ and $60cm-1$. The potential anisotropy is dominated by dipole and quadrupole terms on CH. Bound ro-vibrational eigentates were calculated for various J values and compared with experimental results.