You have to do the spin-polarized calculation for isolated atom. Zr has two unpaired electron in outer d-shell.
On Tue, Jun 4, 2013 at 1:02 PM, Dongsheng Zhang <zhdsheng21 at gmail.com>wrote: > Hi, > > I am calculating the optimum lattice constant nd cohesive energy of Zr hcp > crystal. The total energy of a sinle Zr atom I got from input file Zr.in is > -5.53133015 Ry, the total energy of Zr hcp crystal I got from input file > Zr.hcp.in is -12.13562915 Ry, so the cohesive energy is -0.536 Ry, > converted to -7.30 eV. From a reference paper, the cohesive energy should > be -6.2eV. Attached below are Zr.in and Zr.hcp.in. Could anyone tell me > if I had made any mistake in those input files? Thanks. > > Zr.in: > > &control > prefix='Zr', > pseudo_dir = '/home/zhang/Software/espresso_PP/', > outdir='/share/scratch/tmpZr/eCut120SM0.01/', > / > &system > ibrav= 1, celldm(1) =50, nat= 1, ntyp= 1, > occupations='smearing', smearing='marzari-vanderbilt', degauss=0.01, > ecutwfc =120, > > / > &electrons > / > ATOMIC_SPECIES > Zr 91.224 Zr.pbe-mt_fhi.UPF > ATOMIC_POSITIONS > Zr 0.000000000000 0.000000000000 0.000000000000 > K_POINTS gamma > > > Zr.hcp.in > > &control > prefix='Zr', > pseudo_dir = '/home/zhang/Software/espresso_PP/', > outdir='/share/scratch/tmpZr/eCut120K18hcpSM0.01/', > calculation='vc-relax' > / > &system > ibrav= 4, celldm(1) =6, celldm(3) =1.633, nat= 2, ntyp= 1, > occupations='smearing', smearing='marzari-vanderbilt', degauss=0.01, > ecutwfc =120, > / > &electrons > / > &ions > / > &cell > / > ATOMIC_SPECIES > Zr 91.224 Zr.pbe-mt_fhi.UPF > ATOMIC_POSITIONS crystal > Zr 0.000000000000 0.000000000000 0.000000000000 > Zr 0.666666666666 0.333333333333 0.50000000000 > K_POINTS automatic > 18 18 36 1 1 1 > > PS The optimum lattice constant got from Zr.hcp.in is very close to the > data in literature. > > > I have tried different value of the smearing parameter ranged from 0.001 > to 0.05, none of their cohesive energy is good. > > If the smearing value is 0.1, simulation by zr.in (single atom) will stop > at iteration # 10 without any error message. Why does it happen? > > Thank you for your help, > > Dongsheng > > _______________________________________________ > 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/20130604/faf91c7f/attachment.html