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.
Download (2735kB) | Preview
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:||Colleges and Schools > College of Science & Technology|
Colleges and Schools > College of Science & Technology > School of Computing, Science and Engineering
Colleges and Schools > College of Science & Technology > School of Computing, Science and Engineering > Materials & Physics Research Centre
|Journal or Publication Title:||Canadian Journal of Physics|
|Publisher:||National Research Council Canada|
|Depositing User:||H Kenna|
|Date Deposited:||23 Aug 2007 11:02|
|Last Modified:||27 Sep 2011 12:28|
Document DownloadsMore statistics for this item...
Actions (login required)
|Edit record (repository staff only)|