Hydride bonding - Ab initio studies of BeH2…Li+, BeH2…Na+ and BeH2…Mg2+ model systems

The physical nature of intermolecular interactions in hydride bonded complexes BeH2…Li+, BeH2…Na+ and BeH2…Mg2+ has been examined using 'Atoms in Molecules' (AIM) approach as well as variation-perturbation partitioning of interaction energy. Results obtained at MP2 theory level within series of correlation consistent basis sets: aug-cc-pVDZ, aug-cc-pVTZ and aug-cc-pVQZ yielded binding energies in the range 10-60 kcal/mol, which may indicate possible essential role of hydride bonding in crystal packing. AIM results and the relative magnitude of interaction energy components indicate the unique features of hydride bonds in contrast to its counterparts - the hydrogen and dihydrogen bonding. However, hydride bonds seem to be very similar to agostic interactions.