Comparison of elastic constants and electronic structures in the series ofthe alkaline-earth selenides: a quantum chemical approach

The elastic constants and electronic structure of MgSe, CaSe and SrSe have been calculated using the CRYSTAL95 program which implements the Linear Com bination of Atomic Orbitals-Self Consistent Field method for periodic syste ms. Two levels of calculation have been considered: the Hartree-Fock approa ch and a Density Functional-like hamiltonian in which the exact Hartree-Foc k exchange is supplemented by a local or a gradient corrected term for the correlation potential. Both, all electron and effective core pseudopotentia l results have been presented. The mechanical and electronic properties sho w that the series of selenides is homogeneous, but MgSe presents a few diff erences with respect to CaSe and SrSe from the electronic point of view. (C ) 2000 Elsevier Science Ltd. All rights reserved.