An analytical potential energy surface for P۲-He dimer from ab initi oc alculations

A new potential energy surfa ce (PES) for P۲-He has been calculated using the supermol ecular method at the C oupled-Cluster level with Single and Doub le plus perturbative Triple excitations [CCS D(T)], using a large basis set supplemented with midpoint bond functions. The rigid molecul e approximation has be en used for P۲. Ab initio calculatio ns of the PES of Van der Waals complexes initially reproduce the PES in the form of tables of numbers, which have to be interpolated or extrapolated for desired app lications. To overcome the difficulties of apply a high level post Hartree-Fock method in conjunction with an extended basis set, application of bond functions located s omewhere b etween monomers seems to be a wise soluti on. The CCSD(T) PES is characterized by a global mini mum of -۱۷.۲۰۹ cm-۱ at Re= ۳.۴۱۷ Å and șe =۱۱۶ degree.

کلیدواژه ها:

Vander Waals complex ، Inte rmolecular forces ، P۲-H e dimer ، CCSD(T)