Dear Bo and Lorenzo, I have one more suggestion on the issue of phonon branch sorting. I ran into this problem a while back, while working on a project on thermal transport in indium arsenide nanowires. I ended up using an sorting algorithm that Keith Refson developed for use with phonon calculations in the CASTEP code. This script works by calculating overlap matrices between eigenvectors at neighboring q-points. Keith recently licensed this script as GPL and I have written a tool to convert the matdyn phonon output to the CASTEP phonon format. For my project, I found that as long as you have a fairly dense mesh of q-points, it worked very well.
I am planning to put these scripts up on the web soon once I have a short example run to go with it. I'll send a note to the PWSCF forum when it is ready. Bo, in the meantime, I would be happy to send you the scripts if you are interested. Best regards, Derek ################################ Derek Stewart, Ph. D. Senior Research Associate http://sites.google.com/site/dft4nano/ 250 Duffield Hall Cornell Nanoscale Facility (CNF) Ithaca, NY 14853 stewart (at) cnf.cornell.edu (607) 255-2856 On 10/26/2012 8:00 AM, Lorenzo Paulatto wrote: > On 26 October 2012 07:55, Bo Qiu <200210qb at gmail.com > <mailto:200210qb at gmail.com>> wrote: > > Dear Dr. Paulatto, > > Thanks a lot for the explanations! I'm actually writing a small > code to order phonon bands based on eigenvector continuities on a > 3d grid. Thanks for pointing out there is already such option in > matdyn.x, I'll definitely check it out. I have finished a > preliminary test for my code on Al for a band crossing along > Gamma-K direction -- it seems to be well captured, but band > orderings are wrong at some random point where there is actually > no band crossing. I'll try to figure it out and also referring to > the matdyn.f90 to see what else I can do. > On the other hand, I think for electronic band structures one will > have the same problem with band ordering -- though most of time > people are only interested about those very few bands near Fermi > level. I wonder in the case of electronic band structure whether > continuity of wavefunction should be used to deal with band > ordering with band crossing? Thanks a lot! > > > The bands.x code already does that, i.e. it sorts the bands using the > overlap of wavefunctions at consequent k-points. Again, this is an > option that works well for line plots, but I'm not sure it always make > sense to use in a 3D dispersion. Or at least, it would need to be > modified to sort according to neighboring points, not just according > to the previous point in the input list. It is not very hard to do, > but a bit boring as it requires a rethinking of the code structures. > > bests > > -- > Dr. Lorenzo Paulatto > IdR @ IMPMC -- CNRS & Universit? Paris 6 > phone: +33 (0)1 44275 084 / skype: paulatz > www: http://www-int.impmc.upmc.fr/~paulatto/ > <http://www-int.impmc.upmc.fr/%7Epaulatto/> > mail: 23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05 > > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20121026/fb458362/attachment.html
