MOLECULAR BONDING IN GROUP-IIA DIMERS BE2-BA2

Binding energy curves for low-lying states of Group IIA dimers Be 2-Ba2 have been calculated using the local spin-density functional formalism. Where band spectroscopic data are available (Mg 2, Ca2), the agreement with experiment is generally good. Bonding trends across the series show some remarkable irregularities, which correlate well with trends in the corresponding bulk materials but which do not follow the trend in the atomic polarizabilities. In the density functional picture, the binding in the 1∑+ states is due to sp- and sd -hybridization resulting from the overlap of charge densities on neighboring atoms. Further experimental work, particularly on Be2 and Sr2, is necessary to clarify the nature of bonding in these systems. © 1979 American Institute of Physics.