Dear Dimpy, Dimpy Sharma wrote: > Hi there, > I tried to calculate the ground state energy for isolated hydrogen atom > with the following input,however I got the fermi energy level at > -3.5661eV, while it should be -13.6eV.
I think that in your calculation, the Fermi level will be approximatively equal to the 1s electron energy level. You should be aware that you are using a pseudopotential code: even in the case of a one electron system you won't get something close to the true energy of the 1s level of the hydrogenoid atom unless you use an all-electron formalism (maybe PAW can give a n AE energy estimate). Anyway, another big problem here is the self-interaction error. Even an AE calculation would give you a not so good value, I suspect. Maybe you can get something close to the experimental energy level by using ld1.x (as Lihn suggested) and enabling the self-interaction correction (see Doc/INPUT_LD1.txt). Besides all this, I believe that in general it is better to use fixed occupations from input, rather than smearing, in atomic calculations with pw.x. HTH GS > > &CONTROL. > calculation ='scf' > restart_mode = 'from_scratch' > outdir = '/sfiwork/dsharma/eigenvaluesSi/wf_H/' > pseudo_dir = '/sfiwork/dsharma/QE_Pseudos/' > prefix = 'H' > tstress = .true. > tprnfor = .true. > wf_collect =.true. > / > &SYSTEM > ibrav = 1 > celldm(1) = 15 > nat = 1 > ntyp = 1 > ecutwfc = 40 > ecutrho = 160.0 > nbnd = 2, > nspin=2, > starting_magnetization(1)=0.5 > nosym=.true., > occupations='smearing', > smearing='mp', > degauss=0.01, > > / > &ELECTRONS > diagonalization ='cg' > mixing_mode = 'local-TF' > conv_thr = 1.0d-6 > mixing_beta = 0.7 > / > ATOMIC_SPECIES > H 1.00794 H.pz-vbc.UPF > ATOMIC_POSITIONS angstroms > H 0.0000 0.0000 0.0000 > K_POINTS automatic > 1 1 1 0 0 0 > > Thanks > > Dimpy > UCC > Ireland > > > ------------------------------------------------------------------------ > > _______________________________________________ > 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
