15min:
THE AB INITIO CALCULATION OF THE C3-AR VAN DER WAALS COMPLEX.

BON-GI LIN, SHIH-MING WEN, A. MEBEL AND YEN-CHU HSU, INSTITUTE OF ATOMIC AND MOLECULAR SCIENCES, ACADEMIA SINICA, P. O. BOX 23-166, TAIPEI 107, TAIWAN, R. O. C..

The equilibrium geometry of the ground electronic state of C3Ar has been determined to be T-shaped at the level of CCSD(T)/cc-pVQZ: \ell (C-C) =1.298Å, \angle C-C-C=173.75\circ, \ell (C3-Ar)=3.85Å, \angle C3-Ar=90\circ. Its binding energy is about 130 cm-1 and the vdW stretch is 30 cm-1. The internal rotation of the complex is strongly coupled with the vdW stretch. Other conformers (two in-plane and one out-of-plane) have been identified as the C3 moiety of the complex bends away from the equlibrium angle. The computation results will be used to qualitatively interpret our experimental observations.