Ab-initio density-functional lattice-dynamics studies of ice
Côté, AS, Morrison, I, Cui, XY, Jenkins, S and Ross, DK 2003, 'Ab-initio density-functional lattice-dynamics studies of ice' , Canadian Journal of Physics, 81 (1-2) , pp. 115-122.
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We present the results of first-principles computational studies of the dynamical properties of hexagonal ice using both the ab-initio pseudopotential method and the full-potential augmented plane-wave method. Properties obtained using both the generalized gradient approximation (GGA) and the meta-GGA in density-functional theory are compared. The lattice-dynamical properties of the structures are obtained using a finite-difference evaluation of the dynamical matrix and force-constant matrix from atomic forces. Phonon dispersion is evaluated by the direct determination of the force-constant matrix in supercells derived from the primitive molecule unit cells with the assumption that force constants are zero beyond the second molecular nearest neighbors. The k-dependent phonon frequencies are then obtained from the force-constant matrix and dispersion relations, and the Brillouin-zone integrated density of states is evaluated. The importance of phonon dispersion in the various regions of the phonon spectra is then assessed and compared to existing neutron-scattering data. Frozen-phonon calculations are used to compare phonon frequencies evaluated in both the GGA and meta-GGA.
|Themes:||Subjects / Themes > Q Science > QC Physics
Subjects outside of the University Themes
|Schools:||Schools > School of Computing, Science and Engineering
Schools > School of Computing, Science and Engineering > Salford Innovation Research Centre (SIRC)
|Journal or Publication Title:||Canadian Journal of Physics|
|Publisher:||National Research Council Canada|
|Depositing User:||H Kenna|
|Date Deposited:||23 Aug 2007 10:02|
|Last Modified:||01 Dec 2015 00:03|
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