this might be useful : http://chianti.geol.ucl.ac.uk/~dario/tutorial_phonons.tar.gz
On Fri, Apr 15, 2011 at 12:48 PM, karim rezouali <[email protected]>wrote: > Dear all, > > I am currently working on the phonons in the whole Brillouin -zone of > bulkwurtzite > AlN (VIBRA- supercell of 500 atoms) and I encounter a serious problem with > LO phonons in the limit of gamma. I calculated the Born charges and the > dielectric tensor (LO-TO spleeting) and the results (attached file: > dipersion along gamma point- A point) do not agree with calculations > reported in the litterature using other softwares (linear response method). > I increased the size of the supercell (700 atoms) but no change in the > shape of the LO branch was observed. > > Is the problem intrinsic to SIESTA because no works are available (to my > knowledge) on the whole-Brillouin zone optical phonons using this code in > the literature?!. > > Thanks in advance, > > Karim > > > > > > -- Mehmet Topsakal (Ph.D. Student) UNAM-Institute of Materials Science and Nanotechnology. Bilkent University. 06800 Bilkent, Ankara/Turkey Tel: 0090 312 290 3527 ; Fax: 0090 312 266 4365 http://www.researcherid.com/rid/A-5015-2010
