LDA or GGA? A combined experimental inelastic neutron scattering and ab initio lattice dynamics study of alkali metal hydrides
| Autor: | Daniele Colognesi, G. D. Barrera, Philip C. H. Mitchell, Anibal J. Ramirez-Cuesta |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Inelastic neutron scattering
Alkali metal hydrides Hydrogen storage materials DFT calculations Free energy calculations Thermodynamic properties INS spectra Ab-initio calculations LiH NaH KH RbH CsH Bulk modulus Físico-Química Ciencia de los Polímeros Electroquímica Ab initio General Physics and Astronomy Electronic structure Molecular physics Spectral line Physics::Atomic and Molecular Clusters Physics::Chemical Physics Physical and Theoretical Chemistry Spectroscopy Condensed matter physics Chemistry Alkali metal hydride Ciencias Químicas Abinitio calculations Alkali metal Local-density approximation CIENCIAS NATURALES Y EXACTAS |
| Zdroj: | Chemical physics 317 (2005): 119–129. info:cnr-pdr/source/autori:Barrera G. D.; Colognesi D.; Mitchell P. C. H.; Ramirez-Cuesta A. J./titolo:LDA or GGA? A combined experimental inelastic neutron scattering and ab initio lattice dynamics study of alkali metal hydrides/doi:/rivista:Chemical physics (Print)/anno:2005/pagina_da:119/pagina_a:129/intervallo_pagine:119–129/volume:317 |
| ISSN: | 0301-0104 |
| DOI: | 10.1016/j.chemphys.2005.04.027 |
| Popis: | In a previous work, we carried out inelastic neutron scattering (INS) spectroscopy experiments and preliminary first principles calculations on alkali metal hydrides. The complete series of alkali metal hydrides, LiH, NaH, KH, RbH and CsH was measured in the high-resolution TOSCA INS spectrometer at ISIS. Here, we present the results of ab initio electronic structure calculations of the properties of the alkali metal hydrides using both the local density approximation (LDA) and the generalized gradient approximation (GGA), using the Perdew–Burke–Ernzerhof (PBE) parameterization. Properties calculated were lattice parameters, bulk moduli, dielectric constants, effective charges, electronic densities and inelastic neutron scattering (INS) spectra. We took advantage of the currently available computer power to use full lattice dynamics theory to calculate thermodynamic properties for these materials. For the alkali metal hydrides (LiH, NaH, KH, RbH and CsH) using lattice dynamics, we found that the INS spectra calculated using LDA agreed better with the experimental data than the spectra calculated using GGA. Both zero-point effects and thermal contributions to free energies had an important effect on INS and several thermodynamic properties. Fil: Barrera, Gustavo Daniel. Universidad Nacional de la Patagonia "San Juan Bosco"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Rutherford Appleton Laboratory; Reino Unido Fil: Colognesi, D.. Istituto dei Sistemi Complessi; Italia Fil: Mitchell, P. C. H.. University of Reading; Reino Unido Fil: Ramirez Cuesta, A. J.. University of Reading; Reino Unido. Rutherford Appleton Laboratory; Reino Unido |
| Databáze: | OpenAIRE |
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