Comparison of elastic constants and electronic structures in the series of the 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 Combination of Atomic Orbitals-Self Consistent Field method for periodic systems. Two levels of calculation have been considered: the Hartree-Fock approach and a Density Functional-like hamiltonian in which the exact Hartree-Fock exchange is supplemented by a local or a gradient corrected term for the correlation potential. Both, all electron and effective core pseudopotential results have been presented. The mechanical and electronic properties show that the series of selenides is homogeneous, but MgSe presents a few differences with respect to CaSe and SrSe from the electronic point of view. (C) 2000 Elsevier Science Ltd. All rights reserved.