Symmetry breaking effects in HD⁺

Abstract

Symmetry breaking corrections for HD⁺ are estimated by performing a unitary transformation on the hamiltonian. The terms responsible for g/u coupling are removed from the kinetic energy operator at the expense of introducing additional terms in the potential. The effective electrostatic potential may be interpreted in terms of effective nuclear charges. A new hamiltonian having the correct dissociation limits is obtained and the corresponding Schrödinger equation is largely separable. The resulting corrections to the energy compare well with previous work, particularly at large bond lengths, and the electric dipole moment and electron densities at the nuclei show the correct behaviour near dissociation.