Hi,
You can use options in ph.in file: start_q=5, last_q=5 to calculate phonons for particular q-point(s) from the mesh. The result should not depend on the way how you got these dyn-files (supposing all parameters are the same and correct). The way you used is more convenient for a general q-point not presented in q-mesh. Bests, Eyvaz. ------------------------------------------------------------------- Prof. Eyvaz Isaev, Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com ________________________________ From: Bipul Rakshit <[email protected]> Dynamical matrices for ( 6, 6, 1,) uniform grid of q-points ( 7q-points): N xq(1) xq(2) xq(3) 1 0.000000000 0.000000000 0.000000000 2 0.000000000 0.192450090 0.000000000 3 0.000000000 0.384900179 0.000000000 4 0.000000000 -0.577350269 0.000000000 5 0.166666667 0.288675135 0.000000000 6 0.166666667 0.481125224 0.000000000 7 0.333333333 0.577350269 0.000000000 in my output file. I just want to ask, that is it wise to run the calculation usingldisp =true (graph.ph.in), which calculate the phonon frequencies one by one or Seven different calculations, using the above seven different q-points, using single q-point calculation (graph-singleq.ph.in) Is both the ways gives final result same? Because the latter method takes less time, than previous. thanks -- Bipul Rakshit Research Fellow, S N Bose Centre for Basic Sciences, Salt Lake, Kolkata 700 098 India -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100815/1af77e68/attachment.htm
