Dear PWSCF users, I am doing a scf calculation on si(100) slab surface. I have tested two pseudo potentials fo silicon to see which performs better.
I am wondering why using the Si.pbe-n-van.UPF and Si.pw91-n-van.UPF pseudoes in the first case I can reach quite easily ( after 400 iterations) the convergence while in the latter case after 1200 iterations I still don't reach the convergence. the mixing beta is 0.5. Is there something wrong? Anyway the input file is below: # self-consistent calculation cat > si-ex01.in << EOF &control calculation='scf' prefix='si', tstress = .true. tprnfor = .true. restart_mode='restart', pseudo_dir ='/sfs/sanfs/home/userincm/incbo407/PWscf/pseudo/', outdir='/scratch/incbo407/au-PWscf/tmp-1/', etot_conv_thr = 1.d-4 / &system ibrav = 8, celldm(1) = 29.02243, celldm(2) =1.0, celldm(3)= 0.89771, nat=56, ntyp=2, ecutwfc=18.0, / &electrons mixing_mode = 'plain' mixing_beta = 0.5 conv_thr = 1.0d-8 / &ions / ATOMIC_SPECIES Si 28.086 Si.pw91-n-van.UPF H 1 H.pw91-van_ak.UPF ATOMIC_POSITIONS {angstrom} Si -.486986953827 -.486915661371 .021837699340 Si 3.254734080912 3.254554580350 -.715466406181 Si .424995921464 5.989287334956 -.032510900988 Si 1.908574447668 7.596205581111 -.896329755432 Si 5.990175519344 .425574367605 -.031655667742 Si 7.597289525085 1.909448358802 -.895741285772 Si 4.863694686691 4.863621862511 -.928089502092 Si 9.019734606435 9.020000340300 -.836996926760 Si 1.332006439043 4.282396930595 -1.483511378893 Si 4.282762677873 1.331640602610 -1.482720710139 Si 1.215421638705 9.726643706866 -1.436019240017 Si 4.069065518611 6.940868463489 -1.558148325068 Si 6.941730748367 4.070143770542 -1.556740812199 Si 9.727400143869 1.215885487447 -1.436139812232 Si 6.926671693616 9.825186228268 -1.480679150046 Si 9.825040961721 6.927019069098 -1.481122837636 Si 2.752199364097 -.023268345504 -2.733402882614 Si -.022185141426 2.752036538539 -2.734578963613 Si 2.755879272416 5.496899501655 -2.970326566691 Si -.004779806850 8.317568614429 -2.969974442472 Si 8.317316174588 -.004017804657 -2.969192076227 Si 5.498360672151 2.755878723458 -2.968474960855 Si 8.346177303503 5.558752009571 -2.782863187750 Si 5.557877655641 8.346312021303 -2.782400281184 Si 1.389966664098 1.388183764950 -4.139518840077 Si 1.366337053897 6.940229376004 -4.258916306178 Si 4.151574127028 4.149476803004 -4.278767316434 Si 4.138929512730 9.694066210006 -4.160002340210 Si 6.940071554385 1.366577579401 -4.258586275398 Si 9.693861222560 4.139131304691 -4.160296524367 Si 6.925553051516 6.926722417990 -4.154730726999 Si 9.700291030289 9.701542440060 -4.273212145658 Si .000000000000 .000000000000 -5.538591342479 Si 2.769296729594 2.769296729594 -5.538591342479 Si .000000000000 5.538591342479 -5.538591342479 Si 2.769296729594 8.307892305490 -5.538591342479 Si 5.538591342479 .000000000000 -5.538591342479 Si 8.307892305490 2.769296729594 -5.538591342479 Si 5.538591342479 5.538591342479 -5.538591342479 Si 8.307892305490 8.307892305490 -5.538591342479 H .847478422628 -.846884685755 -6.504440365581 H -.847316494390 .847694326946 -6.503794769337 H 3.610082118376 1.928241460414 -6.515886469477 H 1.917014435899 3.621363118971 -6.495428477030 H .852174341536 4.685717428620 -6.494724671289 H -.840461532306 6.379649786722 -6.516156349874 H 3.616235391428 7.460033933598 -6.504011732009 H 1.921872283045 9.155369669764 -6.503953522512 H 6.383803828126 -.844617690420 -6.508975414605 H 4.685555500382 .852282293694 -6.494454790892 H 9.156068183733 1.921926259125 -6.503307926268 H 7.460679529841 3.616289367507 -6.504710245978 H 6.385587155455 4.690845156163 -6.504170485184 H 4.690683227924 6.386073998525 -6.503524888940 H 9.160391561857 7.455445966849 -6.494835798512 H 7.462679819843 9.153210626588 -6.508329818361 K_POINTS {automatic} 4 4 1 0 0 0 EOF thank you. Francesca Costanzo -- Francesca Costanzo, Ph.D. Dipartimento di Chimica Fisica ed Inorganica Viale Risorgimento 4 40136 Bologna tel.0039-051-2093710 fax 0039-051-2093690