Quantum mechanical Hartree-Fock self-consistent field study of elastic constants and chemical bonding of MgF2 (sellaite)
Articolo
Data di Pubblicazione:
1991
Citazione:
Quantum mechanical Hartree-Fock self-consistent field study of elastic constants and chemical bonding of MgF2 (sellaite) / M. Catti, A. Pavese, R. Dovesi, C. Roetti, M. Causa. - In: PHYSICAL REVIEW. B, CONDENSED MATTER. - ISSN 0163-1829. - 44:8(1991 Aug), pp. 3509-3517.
Abstract:
A periodic ab initio Hartree-Fock method (the program CRYSTAL) has been used to evaluate the total-electron-energy surface of MgF2 (rutile-type tetragonal structure) as a function of crystal strain. Mg and F atoms are represented by 13 atomic orbitals in the form of contracted Gaussian-type functions. The equilibrium unit-cell edges and fluorine coordinates, the binding energy, and the six elastic constants C-11, C-12, C-13, C33, C44, and C66 have been calculated. Inner strain was accounted for by relaxing the F-atom position for each lattice deformation applied, and contributed significantly to the C44, C66, and C33 components. An average deviation of 8.0% is observed with respect to experimental elastic data Classical two-body empirical calculations have been performed for the purpose of comparison. Energy bands, Mulliken electron populations, and charge-density maps are analyzed, and the chemical bonding is discussed, showing significant deviations from ionicity (z(Mg) = 1.80(e)).
Tipologia IRIS:
01 - Articolo su periodico
Elenco autori:
M. Catti, A. Pavese, R. Dovesi, C. Roetti, M. Causa
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