The interaction between He and H+ 2: anisotropy, bond length dependence and hydrogen bonding

Abstract

An extensive high level ab initio study of the ground electronic state of HeH+ 2 has been used to generate an improved intermolecular potential for He + H+ 2 that includes a more complete account of the long range forces, the short range anisotropy, and the dependence of the potential on H+ 2 bond length r. In good agreement with earlier work, the potential is found to have a minimum for collinear geometry, with a well 7.799 kcal mol−1 (2728 cm−1) deep with respect to separated He + H+ 2(r = r e = 1.9982 a 0) at an intermolecular distance R = 2.963 a 0(1.5684 Å) and a bond length r = 2.0742 a 0 (1.098 Å).