Thanks a lot. I will try it. Chengyang
----- Original Message ----- > From: "Yun Wang" <yun.wang at griffith.edu.au> > To: "PWSCF Forum" <pw_forum at pwscf.org> > Sent: Wednesday, April 24, 2013 3:17:38 PM > Subject: Re: [Pw_forum] problems of the K points of the unit cell and > supercell > Hi Chengyang, > You can run a series of calculations with different k-point meshes. > The right k-point mesh density can be determined once the total > energies converge. > Cheers, > Yun > On Thu, Apr 25, 2013 at 5:18 AM, Chengyang Li < > li.chengyang at wmich.edu > wrote: > > Dear all > > > I have a question about the K points. When I try to repeat the unit > > cell to get a supercell. I found someone said if the structure is > > changed, the K points should be changed at the same time if we want > > to keep the same result. I try to calculate the phonon of the > > chromium, the atomic positions and cell parameters are like this: > > > Unit cell > > > ATOMIC_POSITIONS crystal > > > Cr1 0.000000000 0.000000000 0.000000000 > > > CELL_PARAMETERS cubic > > > 0.500000000 0.500000000 0.500000000 > > > -0.500000000 0.500000000 0.500000000 > > > -0.500000000 -0.500000000 0.500000000 > > > Supercell, there are two unit cells in this cell. > > > ATOMIC_POSITIONS crystal > > > Cr1 0.000000000 0.000000000 0.000000000 > > > Cr1 0.000000000 0.000000000 0.500000000 > > > Cr1 0.500000000 0.500000000 0.250000000 > > > Cr1 0.500000000 0.500000000 0.750000000 > > > CELL_PARAMETERS > > > 1.000000000 0.000000000 0.000000000 > > > 0.000000000 1.000000000 0.000000000 > > > 0.000000000 0.000000000 2.000000000 > > > If I set the unit cell like this > > > K_POINTS automatic > > > 4 4 4 1 1 1 > > > How should I change the k points in the supercell? > > > Thank you for the attention. > > > Chengyang Li > > > Western Michigan University, > > > _______________________________________________ > > > Pw_forum mailing list > > > Pw_forum at pwscf.org > > > http://pwscf.org/mailman/listinfo/pw_forum > > -- > Dr. Yun Wang > Research Fellow > Centre for Clean Environment and Energy > Griffith School of Environment > Gold Coast Campus, Griffith University > QLD 4222, Australia > Tel:(61-7) 5552 8456 > Fax:(61-7) 5552 8067 > _______________________________________________ > 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/20130424/0b832560/attachment.html
