The lattice parameter, bulk modulus, and cohesive energy of lithium hydride are calculated to very high accuracy through a combination of periodic and finite-cluster electronic structure calculations. The Hartree-Fock contributions are taken from earlier work in which plane-wave calculations were corrected for pseudo-potential errors. Molecular electronic structure calculations on finite clusters are then used to compute the correlation contributions and finite-size effects are removed through the hierarchical scheme. The systematic improvability of the molecular electronic structure methods makes it possible to converge the static cohesive energy to within a few tenths of a millihartree. Zero-point energy contributions are determined from density functional theory phonon frequencies. All calculated properties of lithium hydride and deuteride agree with empirical observations to within experimental uncertainty.
Calculation of properties of crystalline lithium hydride using correlated wave function theory / Nolan, Sj; Gillan, Mj; Alfe, D; Allan, Nl; Manby, Fr. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 80:16(2009). [10.1103/PhysRevB.80.165109]
Calculation of properties of crystalline lithium hydride using correlated wave function theory
Alfe D;
2009
Abstract
The lattice parameter, bulk modulus, and cohesive energy of lithium hydride are calculated to very high accuracy through a combination of periodic and finite-cluster electronic structure calculations. The Hartree-Fock contributions are taken from earlier work in which plane-wave calculations were corrected for pseudo-potential errors. Molecular electronic structure calculations on finite clusters are then used to compute the correlation contributions and finite-size effects are removed through the hierarchical scheme. The systematic improvability of the molecular electronic structure methods makes it possible to converge the static cohesive energy to within a few tenths of a millihartree. Zero-point energy contributions are determined from density functional theory phonon frequencies. All calculated properties of lithium hydride and deuteride agree with empirical observations to within experimental uncertainty.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.