Electronic and structural properties of CaH2: an ab initio Hartree-Fock study

The Hartree-Fock ab initio method has been used to evaluate some structural and electronic properties of the CaH2 crystal. The calculated quantities i nclude the crystalline parameters, binding energy, elastic constants, band structure, density of states and electronic charge distribution. Taking int o account the correlation effects, the experimental binding energy is well reproduced. The band energies, density of states and charge density maps ar e analyzed, and the nature of chemical bonding is discussed, showing signif icant deviations from ionicity (z(ca) = 1.867\e\). The values of elastic co nstants C-11, C-12, C-13, C-22, C-23, C-33, C-44, C-55, C-66 and bulk modul us, determined for the first time, are 14.4, 110.3, 67.9, 75.1, 143.1, 36.6 , 111.1, 68.7, 81.6 and 202.8 GPa, respectively. (C) 2000 Elsevier Science B.V. All rights reserved.