Hi, I have a problem in constructing the PtH structure. I have prepared the input with following data from J. Phys. Chem. C, 2012, 116 (2), pp 1995--2000 (http://http://pubs.acs.org/doi/abs/10.1021%2Fjp210780m) for hexagonal PtH.
Spacegroup : 194 - P63/mmc Point group : D_6h a=2.795 c=7.769 Pt: 2c (1/3 2/3 0.25) H: 2a ( 0 0 0 ) Point group of this input gives D_3d (-3m) instead of D_6h (6/mmm). I am not sure what am i missing. here is my input for vc-relax under 100GPa (Espresso-4.3.2): &CONTROL calculation = "vc-relax" , restart_mode = 'from_scratch' , outdir='/tmp' , pseudo_dir ='/home/pseudos/espresso/' , etot_conv_thr = 1.0D-14 , forc_conv_thr = 1.0D-5 , prefix='PtH_sp194_100GPa.opt', tstress=.true., verbosity='high' / &SYSTEM ibrav= 4, celldm(1)=5.2817842823, celldm(3)=1.706261153, nat= 4, ntyp= 2, ecutwfc=37 ecutrho = 222 , occupations = 'smearing' , smearing = 'mp' , degauss = 0.02 , / &ELECTRONS conv_thr = 1.0d-7, diagonalization='david' / &IONS ion_dynamics = 'bfgs', / &CELL cell_dynamics = 'bfgs' , cell_factor=1.2, press= 1000.00 / ATOMIC_SPECIES Pt 195.08 Pt.pbe-n-van.UPF H 1.00794 H.pbe-van_ak.UPF ATOMIC_POSITIONS (crystal) Pt 0.333333343 0.666666687 0.250000438 Pt 0.666666627 0.333333313 0.749999562 H 0.000000000 0.000000000 0.000000000 H 0.000000000 0.000000000 0.500000000 K_POINTS automatic 4 4 4 1 1 1 Thanks, Bahadir Altintas University at Buffalo Dept of Chemistry -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120522/e519d3f8/attachment.htm