The unique bonding characteristics of beryllium and the Group IIA metals

The van der Waals potentials of MgCa, MgSr, MgBa, CaSr, CaBa, and SrBa

“…The potentials of MgCa, MgSr, MgBa, CaSr, CaBa, and SrBa obtained from the present simple method are in fair agreement with the existing CCSD(T) results [4]. The general trend predicted by the present method is confirmed by the CCSD(T) results, although the well depths of the present potentials are 1 to 16 percent deeper.…”

“…The results are in a surprisingly good agreement with the potential determined by the laser induced fluorescence spectra of MgCa [3], which is the only experimental result of these molecules that we can find in literature. Compared with the existing ab initio CCSD(T) calculations [4], the depths of the present potential wells are about 1-16 percent deeper.…”

“…In this table, the R e and De calculated with the coupled cluster, single, double and perturbative triple CCSD(T) method by Heaven et al [4] are also shown. The well depths De of the CCSD(T) potentials are shallower by one to sixteen percent compared to the present determinations.…”

“…All in atomic units. [4] between the two atoms, the restoring forces are equal and opposite [16][17][18]. The other derives from an energy dependent hard core model [19].…”

Adsorption of beryllium atoms and clusters both on graphene and in a bilayer of graphite investigated by DFT

“…However, the 2s-2p energy interval is small, 2s electrons can partly be promoted to 2p orbitals, which induces a significant degree of orbital mixing (hybridization) and favours the formation of covalent bonds. It has already been demonstrated that, in the case of beryllium clusters, the degree of hybridization increases with the size of the cluster [14,15]. Another consequence of the small 2s-2p energy interval is that the ground state of simple beryllium compounds is often multi-reference in nature, which is very challenging in computational chemistry.…”