The interaction of MnH(X 7Σ+) with He: Ab initio potential energy surface and bound states

The potential energy surface of the ground state of the He-MnH(X (7)Sigma(+)) van der Waals complex is presented. Within the supermolecular approach of intermolecular energy calculations, a grid of ab initio points was computed at the multireference configuration interaction level using the aug-cc-pVQZ basis set for helium and hydrogen and the relativistic aug-cc-pVQZ-DK basis set for manganese. The potential energy surface was then fitted to a global analytical form which main features are discussed. As a first application of this potential energy surface, we present accurate calculations of bound energy levels of the He-3-MnH and He-4-MnH complexes. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3432762]