Dear Muhammad Zafar: In your structure, were optimized the lattice parameter and atomic positions..?? ecutwfc = 25.0 was obtained after a convergence..?? and finally, may be you need increase the k-points values (after a convergence).
Best PhD stud. Arles V. Gil Rebaza Institute of Physic of La Plata La Plata - Argentine 2011/8/15 zafar rasheed <zafartariq2003 at yahoo.com> > Dear All > > I plot ZnO electronic structure using this file given below > > > > &control > > Title = 'ZnO , hcp,a=3.2500,c=5.206 ,c/a=1.6103125', > > calculation ='scf' > > restart_mode='from_scratch', > > pseudo_dir = '/root/Pwscf/pseudo/', > > outdir ='/root/Pwscf/scratch/' > > prefix ='ZnO' > > tstress = .false. > > tprnfor = .false. > > / > > &system > > ibrav= 4, > > celldm(1) = 6.132075472, > > celldm(3) = 1.601846154, > > nat =4, > > ntyp =2, > > ecutwfc =25.0, > > ecutrho =300.0 > > occupations ='smearing', > > smearing='methefessel_paxton', > > degauss = 0.05, > > / > > &electrons > > diagonalization='cg' , > > conv_thr = 1.0e-8 > > mixing_beta = 0.7 > > / > > ATOMIC_SPECIES > > Zn 65.409 Zn.pz-van_ak.UPF > > O 15.9994 O.pz-van_ak.UPF > > ATOMIC_POSITIONS (crystal) > > Zn 0.333333333 0.666666667 0.0000000 > > O 0.333333333 0.666666667 0.3817000 > > Zn 0.666666667 0.333333333 0.5000000 > > O 0.666666667 0.333333333 0.8817000 > > K_POINTS (automatic) > > 4 4 4 0 0 0 > > > > This plot (after changing scf to nscf) is same as experimental and > theoretical > > > > BUT > > > when I make a cell of 8 atoms (1x1x2 supercell) > > input is as below > > > > &control > > calculation ='scf' > > restart_mode='from_scratch', > > pseudo_dir = '/root/Pwscf/pseudo/', > > outdir ='/root/Pwscf/scratch/' > > prefix ='ZnO' > > tstress = .false. > > tprnfor = .true. > > / > > &system > > ibrav = 4, > > celldm(1) = 6.132075472, > > celldm(3) = 3.203692308, (due to increase in size along Z-direction C= 2*c > ) > > nat = 8, > > ntyp = 2, > > ecutwfc = 25.0, > > ecutrho = 300.0 > > occupations ='smearing', > > smearing ='methefessel_paxton', > > degauss =0.02 > > / > > &electrons > > diagonalization='cg' ,mixing_mode='plain', > > conv_thr = 1.0e-8 > > mixing_beta = 0.7 > > / > > ATOMIC_SPECIES > > Zn 65.38 Zn.pz-van_ak.UPF > > O 16.00 O.pz-van_ak.UPF > > ATOMIC_POSITIONS (crystal) > > Zn 0.333333333 0.666666667 0.000000000 > > Zn 0.333333333 0.666666667 0.500000000 > > Zn 0.666666667 0.333333333 0.250000000 > > Zn 0.666666667 0.333333333 0.750000000 > > O 0.333333333 0.666666667 0.190850000 > > O 0.333333333 0.666666667 0.690850000 > > O 0.666666667 0.333333333 0.440850000 > > O 0.666666667 0.333333333 0.940850000 > > K_POINTS (automatic) > > 4 4 4 0 0 0 > > > After changing scf to bands the electronic structure is metallic (no band > gap) and a I get different electronic structure . Now please guide me how I > can get true electronic structure. > > > Thanking in Advance > > > Muhammad Zafar > PhD Scholar > Department of Physics > The Islamia University of Bahawalpur,Pakistan > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > -- ###---------> Arles V. <---------### -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20110815/c24db579/attachment-0001.htm
