Ab initio calculations of elastic properties and electronic structure of calcium selenide

The elastic constants and electronic structure of CaSe have been investigat ed using the ab initio periodic linear combination of atomic orbitals metho d implemented in the program CRYSTAL 95. Calcium and selenium are described by all-electron and relativistic pseudopotential basis sets, respectively. The geometry has been optimized within both Hartree-Fock approximation and hybrid method, mixing exact-exchange-potential with a correlation potentia l expressed either in the Local Density or Generalized Gradient Approximati ons. The elastic constant tensor and electronic structure of CaSe have been deduced for the two schemes of calculation and compared. (C) 2000 Elsevier Science Ltd. All rights reserved.