Hi again, I assume total energy calculations are more accurate using the tetrahedra method rather than MP k-points. For "smearing" option one has to check also "degauss".
Bests, Eyvaz. --- Marco Fornari <fornari at phy.cmich.edu> wrote: > Hello, > > it may be a problem with the augmented charges of > the pseudopotential. > Try to increase ecutrho to explore this > possibilities. > Best, > Marco > > > Dear all, > > I do a calculation to get the lattice constant of > Ni crystal. > > I scan the lattice constant from 6.60 to 6.70 a.u. > using the bash file > > below. The experimental value is 6.66 and is > consistent with my result. > > But it is clear that the curve departs into two > parts at 6.66. > > (see the picture at > http://www.bsc.ustc.edu.cn/~dxl/download/Graph1.JPG) > > Would you tell my why and how to solve this > problem. > > > > Thank you! > > > > Ding Xunlei > > > > for a0 in 6.60 6.61 6.62 6.63 6.64 6.65 6.66 6.67 > 6.68 6.69 6.70 > > do > > cat >test.in<<! > > &control > > calculation='scf' > > restart_mode='from_scratch', > > pseudo_dir = '/home/bsc/dxl/pseudo/', > > outdir='./' > > prefix='zz' > > tprnfor = .true., > > for a0 in 6.64 > > do > > cat >test.in<<! > > &control > > calculation='scf' > > for a0 in 6.65 > > do > > cat >test.in<<! > > &control > > calculation='scf' > > restart_mode='from_scratch', > > pseudo_dir = '/home/bsc/dxl/pseudo/', > > outdir='./' > > prefix='zz' > > tprnfor = .true., > > tstress = .true. > > / > > &system > > ibrav=2, celldm(1) =$a0 > > nat=1,ntyp=1, > > nspin = 2, starting_magnetization(1)=0.7, > > ecutwfc = 24.0, ecutrho = 288.0, > > occupations='smearing', > smearing='methfessel-paxton', degauss=0.01 > > / > > &electrons > > electron_maxstep= 200 > > diagonalization='' > > conv_thr = 1.0e-8 > > mixing_beta = 0.2 > > &cell > > cell_dynamics = 'none' > > cell_factor = 1.2 > > / > > &ions > > ion_dynamics = 'damp' > > > > / > > ATOMIC_SPECIES > > Ni 58.69 Ni.pbe-nd-rrkjus.UPF > > ATOMIC_POSITIONS > > Ni 0.00000000 0.000000000 0.000000000 > 1 1 1 > > K_POINTS (automatic) > > 13 13 13 1 1 1 > > ! > > > > > > > > > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > ______________________________________________________ Click here to donate to the Hurricane Katrina relief effort. http://store.yahoo.com/redcross-donate3/
