Adiabatic Corrections to Long-Range Born–Oppenheimer Interatomic Potentials

Abstract

The rotationally coupled electronic equations of the previously derived “best adiabatic” (BA) approximation are solved variationally at large values of the internuclear distance. Adiabatic interatomic potentials result which contain all first‐order corrections to the Born–Oppenheimer approximation and change smoothly as the internuclear distance changes. The angular momenta smoothly couple and uncouple resolving difficulties of earlier treatments with corrections to the centrifugal potential. Selection rules for the long‐range corrections to the Born–Oppenheimer (BO) approximation are given. And the long‐range adiabatic potentials in H2 and OH are calculated as examples.