Towards accurate ab initio calculations on the vibrational modes of the alkaline earth metal hydrides

The fundamental modes of the alkaline earth metal hydrides (BeH2, MgH2, CaH2) and their dimers, HX(H)2XH, have been studied by vibrational configuration-interaction calculations based on very accurate potential energy surfaces. Comparison with experimental data obtained from matrix isolation and gas phase measurements is provided and the agreement was found to be excellent for the monomers but poor for the dimers. In addition, many fundamental bands are predicted which have not yet been detected experimentally.