Did you try using different initial spin configurations? If your interested in FM ground state then may be you should try initial magnetic configuration as FM. e.g. +1, +1 for both.
On Wed, Mar 13, 2013 at 9:03 PM, ?? <taokun76 at gmail.com> wrote: > Thank you for your suggestions. When I set two atoms in the unit cell > to be antiferromagnetic, the "total magnetization" is nearly zero, and > the "absolute magnetization" is about 14.67. And the magnetic moment > for two atoms are about 7.16 and -7.18, which is more or less > acceptable. > > Now, the question is that why "total magnetization" and "absolute > magnetization" differs so much if I want to force two atoms into a > ferromagnetic configuration. > > Any suggestions? Thanks! > > With regards, > Kun Tao > > > On 13 March 2013 11:14, Andrei Malashevich <andrei.malashevich at yale.edu> > wrote: > > If you want to model antiferromagnetic structure, you should define two > > types of atoms, Gd1 and Gd2. > > Change ntyp to 2. Use, e.g., > > starting_magnetization(1)=1.0 > > starting_magnetization(2)=-1.0 > > > > ATOMIC_SPECIES > > Gd1 1.0 Gd.GGA-PBE-paw.UPF > > Gd2 1.0 Gd.GGA-PBE-paw.UPF > > ATOMIC_POSITIONS {crystal} > > Gd1 0.33333333 0.66666667 0.25 > > Gd2 0.66666667 0.33333333 0.75 > > > > > > On Wed, Mar 13, 2013 at 11:05 AM, ?? <taokun76 at gmail.com> wrote: > >> > >> Hi, > >> > >> Yes, the bulk Gd without Hubbard U is antiferromagnetic. If I set the > >> two atoms in the unit cell to be antiferromagnetic, the "total > >> magnetization" should be equal to zero, and the "absolute > >> magnetization" is what I have gotten. Now, however, the "total > >> magnetization" is not zero. Could you give me some suggestions? > >> Thanks! > >> > >> With regards, > >> Kun Tao > >> > >> On 13 March 2013 10:48, Stefano de Gironcoli <degironc at sissa.it> wrote: > >> > are you sure you are defining the correct magnetic structure ? > >> > is Gd maybe antiferromagnetic ? > >> > stefano > >> > > >> > On 03/13/2013 03:19 PM, ?? wrote: > >> >> Dear everyone, > >> >> > >> >> I want to calculate the magnetic properties of bulk Gd whose magnetic > >> >> moment is about 8 Bohr magneto/atom. Usually, in the output file > >> >> values of "total magnetization" and "absolute magnetization" should > be > >> >> nearly the same. However, in my output file, I found a big difference > >> >> between them as following: > >> >> > >> >> total magnetization = 8.00 Bohr mag/cell > >> >> absolute magnetization = 15.72 Bohr mag/cell > >> >> > >> >> The good news is that the "absolute magnetization" is close to the > >> >> experimental results (7.86 Bohr mag/atom), the bad news is that the > >> >> "total magnetization" is wrong. Moreover, when I try to calculate the > >> >> magnetic moment on each atom with projwfc.x program, I got about 4.1 > >> >> Bohr mag/atom. > >> >> > >> >> Could you give me some suggestions? Any advice are appreciated, > thanks! > >> >> > >> >> Regards, > >> >> Kun Tao > >> >> > >> >> > >> >> Attached below is the input file: > >> >> > >> >> &control > >> >> calculation='scf' > >> >> restart_mode='from_scratch', > >> >> prefix='Gd', > >> >> pseudo_dir = './' > >> >> outdir='./', > >> >> / > >> >> &system > >> >> ibrav= 4, celldm(1)= 6.96, celldm(3)= 1.59, > >> >> nat= 2, ntyp=1, > >> >> nspin = 2, > >> >> starting_magnetization(1)=1.0, > >> >> ecutwfc=55.0, > >> >> ecutrho=220.0, > >> >> occupations ='smearing', > >> >> smearing ='gauss', > >> >> degauss = 0.01, > >> >> / > >> >> &electrons > >> >> diagonalization='david', > >> >> mixing_beta = 0.3, > >> >> conv_thr = 1.0d-8, > >> >> / > >> >> ATOMIC_SPECIES > >> >> Gd 1.0 Gd.GGA-PBE-paw.UPF > >> >> ATOMIC_POSITIONS {crystal} > >> >> Gd 0.33333333 0.66666667 0.25 > >> >> Gd 0.66666667 0.33333333 0.75 > >> >> K_POINTS {automatic} > >> >> 4 4 4 0 0 0 > >> >> _______________________________________________ > >> >> Pw_forum mailing list > >> >> Pw_forum at pwscf.org > >> >> http://pwscf.org/mailman/listinfo/pw_forum > >> > > >> > _______________________________________________ > >> > Pw_forum mailing list > >> > Pw_forum at pwscf.org > >> > http://pwscf.org/mailman/listinfo/pw_forum > >> > >> _______________________________________________ > >> Pw_forum mailing list > >> Pw_forum at pwscf.org > >> http://pwscf.org/mailman/listinfo/pw_forum > > > > > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://pwscf.org/mailman/listinfo/pw_forum > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > -- Regards, MOHNISH, ----------------------------------------------------------------- Mohnish Pandey, PhD Student, Center for Atomic Scale Materials Design, Department of Physics, Technical University of Denmark ----------------------------------------------------------------- -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20130313/1b9514f7/attachment.html