Dear Amin Torabi you are performing a variable-cell MD simulation therefore the enthalpy is not minimized by the Newton equations for atoms+cell are integrated to give you the dynamics around the target pressure (P=0 in your case). to get the relaxation you should use calculation = "vc-relax" and then choose the minimization strategy. the default is bfgs but also damp dynamics is available. check the relevant input variables: ion_dynamics and cell_dynamics.
best regards, stefano On 10/28/2011 02:49 AM, Amin Torabi wrote: > Dear QE users, > > Will you please do me a favor and take a look at my input file, below. > The total energy and force do not converge and keep oscillating... > I have tried different dt (between 20-70) and wmass, and still not able to > relax the structure > Any comment on my the input_cards here (k-point,ecut,pp,conv...?) > > Many thanks > > > > &CONTROL > calculation = 'vc-md' > pseudo_dir = './' > outdir = './' > prefix = 'dt20' > tstress = .true > tprnfor = .true > nstep = 100 > dt = 20 > / > &SYSTEM > ibrav = 12 > celldm(1) = 8.3147 > celldm(2) = 1.3 > celldm(3) = 1.4772 > celldm(4) = -0.260 > nat = 16 > ntyp = 2 > ecutwfc = 85 > ecutrho = 1100 > input_dft = 'pbesol' > nosym = .true > / > &ELECTRONS > conv_thr = 1.0D-9 > / > &IONS > pot_extrapolation='second-order' > wfc_extrapolation='second-order' > ion_temperature = 'rescaling' > tempw = 300 > / > &CELL > press = 0 > cell_dynamics = 'w' > wmass = 4.2 > / > ATOMIC_SPECIES > B 10.811 B.pbe-n-van.UPF > H 1.00794 H.pbe-van_bm.UPF > ATOMIC_POSITIONS crystal > B 0.005259620 0.145596712 0.040564862 > H -0.199830030 0.176142715 0.150841828 > H 0.217291388 0.312290957 -0.013967013 > H 0.124960907 -0.022012847 0.122883862 > B -0.005259620 -0.145596712 -0.040564862 > H 0.199830030 -0.176142715 -0.150841828 > H -0.217291388 -0.312290957 0.013967013 > H -0.124960907 0.022012847 -0.122883862 > B 0.494739818 0.354404554 0.540568678 > H 0.699828966 0.323861788 0.650847745 > H 0.282707973 0.187708799 0.486039576 > H 0.375038882 0.522017144 0.622882523 > B 0.505260182 0.645595446 0.459431322 > H 0.300171034 0.676138212 0.349152255 > H 0.717292027 0.812291201 0.513960424 > H 0.624961118 0.477982856 0.377117477 > K_POINTS automatic > 8 8 8 0 0 0 > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20111028/a5f8adec/attachment.htm
