Please see some slides and an example (graphite) here: http://www.fisica.uniud.it/~giannozz/Public/vdw.tar.gz P.
On Fri, 2014-10-17 at 18:56 +0800, plgong wrote: > Dear pwscf user, > Recently, I calculated Bilayer graphene with vdw correction. In version of > 4.3, the parameter of London can be set to 'true' > and then add vdw correction to Exc. In version of 5.1, more options can do > it, such as, 'grimmer-d2', 'dft-d'. However, many tests have been performed > but I cannot get the layer-distance (3.34 angstrom in experiment). I uesd > GGA-PBE and LDA-PZ with vdw, recepetively. The final results shows small > distance (3.0 angstrom). I donnot know why leads to the small distance. So, > I still tested the Ecut (30Ry-60Ry0) and vaccum (10-20 angstrom), but the > problem was the same. > The input file is, > > &CONTROL > calculation = 'relax' , > outdir ='./tmp' , > restart_mode = 'from_scratch' , > pseudo_dir ='/home/plgong/pseudo', > etot_conv_thr = 1.0e-4 , > forc_conv_thr = 1.0e-3 , > prefix='graphene', > / > &SYSTEM > ibrav = 4, > a =2.46 > c =10.0 > nat = 4, > ntyp = 1, > ecutwfc = 30.D0 , > ecutrho = 240.0 , > vdw_corr='grimme-d2' > tot_charge = 0.00, > occupations = 'smearing' , > degauss = 0.02 , > smearing='mv' > > / > &ELECTRONS > conv_thr = 1.D-7 , > mixing_beta=0.3 > mixing_mode='local-TF' > electron_maxstep=300 > / > &IONS > ion_dynamics = 'bfgs' , > > / > ATOMIC_SPECIES > C 12.00000 C.pz-rrkjus.UPF > ATOMIC_POSITIONS {crystal} > C 0.000000 0.000000 0.500000 > C 0.333333 0.666667 0.500000 > C 0.000000 0.000000 0.834000 > C 0.666667 0.333333 0.834000 > K_POINTS {automatic} > 30 30 1 0 0 0 > > Can anyone help me to solve it? > > P. L. Gong > ISSP CAS, HeFei, China > > > > -- > > ==================================================== > Addr: Institute of Solid State Physics, Chinese Academy of > Sciences, Hefei, Anhui 230031, China > Tel: +86-551-65591591(office), 18756086113(cell phone) > Email: plg...@theory.issp.ac.cn > ======================================================================== > > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 _______________________________________________ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum