If ibrav=0, you must NOT specify celldm(2-6), according to the manual. http://www.quantum-espresso.org/input-syntax/INPUT_PW.html#id3775702
More info can be found there in regarding celldm, ibrav, CELL_PARAMETTERS PS: you should not change subject of your email. This would help to keep your email in the same thread, and help others to understand well your situation. -------------------------------------------------- Duy Le PhD Candidate Department of Physics University of Central Florida. "Men don't need hand to do things" On Thu, Aug 4, 2011 at 1:06 PM, dipak thakur <deepak.p.thakur at gmail.com> wrote: > Sir, > > Good evening. > > I think I was unable to convey my message correctly. > > Kindly go through the input file below. > --------------------------------------------------------------------------------------------------------- > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > ?&CONTROL > ?????????????????????? title = Graphene mono layer , > ???????????????? calculation = 'relax' , > ??????????????? restart_mode = 'from_scratch' , > ????????????????????? outdir = '/root/tmp/' , > ????????????????? pseudo_dir = '/root/Desktop/QUANTUM_ESPRESSO/pseudo/' , > ????????????????????? prefix = graphene , > ???????????????????? disk_io = 'default' , > ?????????????????? verbosity = 'default' , > ?????????????? etot_conv_thr = 1.D-4 , > ?????????????? forc_conv_thr = 1.D-3 , > ?????????????????????? nstep = 50 , > ????????????????????????? dt = 40 , > ?/ > ?&SYSTEM > ?????????????????????? ibrav = 0, > ?????????????????? celldm(1) = 1.0000000, > ??? ??? ? ? ? ? ?? celldm(2) = 1.0000000, > ??? ??? ? ? ? ? ?? celldm(3) = 0.5000000, > ???????????????????????? nat = 32, > ??????????????????????? ntyp = 1, > ???????????????????? ecutwfc = 50 , > ???????????????????? ecutrho = 400 , > ???????????????? occupations = 'smearing' , > ??????????????????? smearing = 'methfessel-paxton' , > ?????????????????????? nspin = 1 , > ????????????????? lda_plus_u = .false. , > ?/ > ?&ELECTRONS > ??????????? electron_maxstep = 300, > ??????????????????? conv_thr = 1.0d-8 , > ???????????????? mixing_mode = 'plain' , > ???????????????? mixing_beta = 0.5 , > ???????????? diagonalization = 'cg' , > ??????????? diago_cg_maxiter = 50, > ?/ > ?&IONS > ?/ > CELL_PARAMETERS > ??? 16.121319540??? 9.383047808??? 0.000000000 > ???? 0.000000000?? 18.658162370??? 0.000000000 > ???? 0.000000000??? 0.000000000?? 56.689342400 > ATOMIC_SPECIES > ??? C?? 12.01070? C.pbe-van_bm.UPF > ATOMIC_POSITIONS angstrom > ??? C????? 2.891630000??? 7.402190000??? 2.000000000 > ??? C????? 3.592920000??? 8.638320000??? 2.000000000 > ??? C????? 3.603490000??? 6.167020000??? 2.000000000 > ??? C????? 5.018600000??? 8.645010000??? 2.000000000 > ??? C????? 5.021500000??? 6.165980000??? 2.000000000 > ??? C????? 5.733020000??? 7.405220000??? 2.000000000 > ??? C????? 1.471840000??? 7.396160000??? 2.000000000 > ??? C????? 2.891120000??? 9.870660000??? 2.000000000 > ??? C????? 2.894710000??? 4.932640000??? 2.000000000 > ??? C????? 5.733190000??? 9.888500000??? 2.000000000 > ??? C????? 5.736430000??? 4.941300000??? 2.000000000 > ??? C????? 7.163480000??? 7.412030000??? 2.000000000 > ??? C????? 1.474740000??? 4.926900000??? 2.000000000 > ??? C????? 0.762281000??? 8.627830000??? 2.000000000 > ??? C????? 0.763134000??? 6.161720000??? 2.000000000 > ??? C????? 1.471500000??? 9.863350000??? 2.000000000 > ??? C????? 3.603410000?? 11.109500000??? 2.000000000 > ??? C????? 5.021240000?? 11.123900000??? 2.000000000 > ??? C????? 3.605120000??? 3.701560000??? 2.000000000 > ??? C????? 5.026450000??? 3.707890000??? 2.000000000 > ??? C????? 7.878070000??? 8.655320000??? 2.000000000 > ??? C????? 7.163730000??? 9.894970000??? 2.000000000 > ??? C????? 7.162030000??? 4.948140000??? 2.000000000 > ??? C????? 7.876190000??? 6.176770000??? 2.000000000 > ??? C????? 5.736340000?? 12.352200000??? 2.000000000 > ??? C????? 0.772689000??? 3.691020000??? 2.000000000 > ??? C????? 0.762793000??? 1.220030000??? 2.000000000 > ??? C????? 7.876450000?? 11.133700000??? 2.000000000 > ??? C????? 7.162030000?? 12.358700000??? 2.000000000 > ??? C????? 7.872010000?? 13.592200000??? 2.000000000 > ??? C????? 2.894790000??? 2.466190000??? 2.000000000 > ??? C????? 1.474820000??? 2.458780000??? 2.000000000 > K_POINTS automatic > ? 6 6 1?? 1 1 1 > > --------------------------------------------------------------------------------------------------------- > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > I am desparately trying to understand how to determine: > 1. The > CELL_PARAMETERS > ??? 16.121319540??? 9.383047808??? 0.000000000 > ???? 0.000000000?? 18.658162370??? 0.000000000 > ???? 0.000000000??? 0.000000000?? 56.689342400 > (or how are they determined in this case) - This is again a copy of earlier > post. > 2. The????????? celldm(1) = 1.0000000, > ??? ??? ? ? ? ? ?? celldm(2) = 1.0000000, > ??? ??? ? ? ? ? ?? celldm(3) = 0.5000000, > ?????????????????? How do I fix them. > Is there any software and/or technique to do this? or Is there any > mathematical relation that would be able to provide me these values. > The cell parameters are given to a precision upto 9th decimal place. > > Secondly, the celldm(3) =0.5, does it mean that it would divide the value > 56.689342400 by 2 and can similar logic be applied to celldm(1) and > celldm(2)? > Thirdly, if I view the geometry in XcrySDen, it show vacuum layers in Z > direction, but no gap/vacuum in x and y direction? I have seen this in many > papers published till date and is trying to understand these things. > Doesn't the adjacent supercell (in x and y direction) interact with the > supercell under consideration? > Also is there relation between the co-ordinates of the atom, the CELL > PARAMETERS and celldm()? > > I hereby request you to kindly help me in this regard. > > Deepak Thakur > Research Student > Swami Ramanand Teerth Marathwada University, > Vishnupuri, Nanded, > Maharashtra, > India. > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > >
