Hi Cyrille, I completely forgot about declaring the second atom. I will try it again with the starting magnetizations you have suggested, and I will declare the second atom this time. I will also turn off lspinorbit.
Thank you again for your help. All the best, Ben > You can only use lspinorbit=.true. if you have a relativistic pseudo which > not the case of my pseudo... > In any case I do not think spin-orbit coupling will change very much your > bulk modulus. > SOC is just a tiny effect on total energy, at least for 3d metals... > > The most important thing is that you describe properly the AF state. Why do > you initialize the magnetization with > starting_magnetization(1)=0.7, > starting_magnetization(2)=-0.4, > breaking the symmetry between the two atoms. > Furthermore you have declared only one type of atoms while you have two > types.. > I guess you will endup with the non-magnetic solution in your case.. > > You should declare ntype=2 > and > starting_magnetization(1)=0.3, > starting_magnetization(2)=-0.3, > > > hth > cyrille > > ----------------------------------------------------------------------------------------------------------- > Cyrille Barreteau > CEA Saclay, IRAMIS, SPCSI, Bat. 462 > 91191 Gif sur Yvette Cedex, FRANCE > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > phone: +33 (0)1 69 08 29 51 / +33 (0)6 47 53 66 52 > fax : +33 (0)1 69 08 84 46 > email: cyrille.barreteau at cea.fr > Web: http://iramis.cea.fr/Pisp/cyrille.barreteau/ > > ----------------------------------------------------------------------------------------------------------- > > ________________________________________ > De : pw_forum-bounces at pwscf.org [pw_forum-bounces at pwscf.org] de la part > de Ben Palmer [benpalmer1983 at gmail.com] > Date d'envoi : jeudi 6 juin 2013 18:27 > ? : PWSCF Forum > Objet : [Pw_forum] Noncolin vs Nspin=1 for Chromium > > Hi Everyone, > > I've been using a few of the supplied PPs and one kindly suggested/sent > to me by Derek/Cyrille. I've used these to try to calculate the bulk > modulus. First, I used nspin = 1 and with the latest PP ended with a > bulk modulus of 268GPa. I then repeated with noncolin=.true. and > lspinorb=.true. and I was expecting a different result, but at the end > it gave me 268GPa again. I was just wondering whether I'd missed > something in my input script, or whether I'd made any obvious errors? > > This is one of my nspin=1 input files: > > &CONTROL > restart_mode='from_scratch', > calculation=scf, > etot_conv_thr=1.0E-7, > forc_conv_thr=1.0D-6, > nstep=200, > prefix="7ca5bad5d48c", > pseudo_dir="/gpfs/bb/bxp912/pseudopotentials/", > outdir="/gpfs/bb/bxp912/scratch/", > / > &SYSTEM > ibrav=14, > celldm(1)=5.36800113, > celldm(2)=1, > celldm(3)=1, > celldm(4)=0, > celldm(5)=0, > celldm(6)=0, > nat=2, > ntyp=1, > ecutwfc=600, > ecutrho=2400, > occupations='smearing', > smearing='mv', > degauss=0.1, > / > &ELECTRONS > diagonalization='david', > mixing_mode='plain', > mixing_beta=0.7, > conv_thr=1.0D-7, > / > &IONS > ion_dynamics='bfgs', > / > &CELL > cell_dynamics='bfgs', > press=0.0, > cell_factor=2.0, > / > ATOMIC_SPECIES > Cr 51.9961 Cr.pbe-us_norel_cyrille.UPF > ATOMIC_POSITIONS crystal > Cr 0.0000000000 0.0000000000 0.0000000000 > Cr 0.5000000000 0.5000000000 0.5000000000 > K_POINTS automatic > 8 8 8 1 1 1 > > And this is one of my noncolin input files: > > &CONTROL > restart_mode='from_scratch', > calculation=scf, > etot_conv_thr=1.0E-7, > forc_conv_thr=1.0D-6, > nstep=200, > prefix="c7700ccaacf", > pseudo_dir="/gpfs/bb/bxp912/pseudopotentials/", > outdir="/gpfs/bb/bxp912/scratch/", > / > &SYSTEM > ibrav=14, > celldm(1)=5.4753116928, > celldm(2)=1, > celldm(3)=1, > celldm(4)=0, > celldm(5)=0, > celldm(6)=0, > nat=2, > ntyp=1, > ecutwfc=400, > ecutrho=1200, > occupations='smearing', > smearing='mv', > degauss=0.1, > noncolin=.true., > lspinorb=.true., > starting_magnetization(1)=0.7, > starting_magnetization(2)=-0.4, > / > &ELECTRONS > diagonalization='david', > mixing_mode='plain', > mixing_beta=0.7, > conv_thr=1.0D-7, > / > &IONS > ion_dynamics='bfgs', > / > &CELL > cell_dynamics='bfgs', > press=0.0, > cell_factor=2.0, > / > ATOMIC_SPECIES > Cr 51.9961 Cr.pbe-us_norel_cyrille.UPF > ATOMIC_POSITIONS crystal > Cr 0.0000000000 0.0000000000 0.0000000000 > Cr 0.5000000000 0.5000000000 0.5000000000 > K_POINTS automatic > 8 8 8 1 1 1 > > All the best, > > Ben > > _______________________________________________ > 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