mohnish pandey wrote: > Dear users! > I am calculating the energy of gallium nitride thin > films of thickness of 1-10 layers. I am giving 'nstep' equal to 200 but > the output file is not showing any message of convergence. The program > is just completing the 200 iterations. I have played with all the
Iterations in the electronic self-consistent loop or iterations (displacements) in the ionic trajectory? Be careful that nstep refers to the latter, while electron_maxstep to the former. I suppose you are speaking of the electronic convergence. > parameters like 'mixing', 'smearing', etc. I am pasting the input file > for 9 layer calculation. Can anybody please point out my mistake and Have you tried to converge (in a scf run) the respective bulk phases before starting a complicated calculation in a complicated geometry? It' always better start with simple things and understand them before moving to more complicated (=interesting) cases. In you input file I see some problems: 1.Since you are using ultrasoft, you need to specify a meaningful value of ecutrho. Maybe you also need to increase ecutwfc. 2.Have you tried to visualize your structure (for instance with xcrysden) to see if all atoms are in the right place? 3.Why do you remove symmetry? It usually helps convergence GS > get me out of it. > Sincere Thanks in advance. > > > &control > calculation = 'vc-relax', > restart_mode='restart', > nstep=200, > outdir='/home/rajpala/Desktop/wurtzite9', > pseudo_dir='/home/rajpala/Desktop/wurtzite9' > prefix='gan', > tstress = .true., > tprnfor = .true., > / > &system > nosym =.TRUE.,ibrav= 4, a = 3.1427, c = 45,nat= 18, ntyp= 2, > ecutwfc = 25,occupations='smearing',degauss=.02,smearing='m-v' > / > &electrons > diagonalization='david' > mixing_mode = 'local-TF' > mixing_beta = 0.1 > electron_maxstep=200 > conv_thr = 1.0d-6 > / > &IONS > ion_dynamics='bfgs' > / > &CELL > cell_dynamics='damp-w' > / > ATOMIC_SPECIES > Ga 69.723 Ga.pbe-nsp-van.UPF > N 14.0067 N.pbe-rrkjus.UPF > ATOMIC_POSITIONS (crystal) > Ga 0.33333333 0.66666666 0.0577 > Ga 0.33333333 0.66666666 0.17327 > Ga 0.00 0.00 0.1154 > Ga 0.00 0.00 0.23105 > Ga 0.33333333 0.66666666 0.288 > Ga 0.00 0.00 0.3459 > Ga 0.33333333 0.66666666 0.4045 > Ga 0.00 0.00 0.4623 > Ga 0.33333333 0.66666666 0.5206 > N 0.0 0.0 0.0398 > N 0.0 0.0 0.1553 > N 0.33333333 0.66666666 0.0957 > N 0.33333333 0.66666666 0.2130 > N 0.0 0.0 0.2708 > N 0.33333333 0.66666666 0.3279 > N 0.0 0.0 0.3873 > N 0.33333333 0.66666666 0.4443 > N 0.0 0.0 0.5035 > K_POINTS (automatic) > 6 6 1 0 0 0 > > > -- > Mohnish Pandey > Y6262,4th Year Undergraduate, > Department of Chemical Engineering, > IIT KANPUR > > > ------------------------------------------------------------------------ > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum -- o ------------------------------------------------ o | Gabriele Sclauzero, PhD Student | | c/o: SISSA & CNR-INFM Democritos, | | via Beirut 2-4, 34014 Trieste (Italy) | | email: sclauzer at sissa.it | | phone: +39 040 3787 511 | | skype: gurlonotturno | o ------------------------------------------------ o
