If I remember correctly anatase has 12 atoms in a simple tetragonal unit cell. This is an example of input data I found in my disk.
Note that HGH pseudopotentials are 1) very hard: 40 Ry for wavefunctions is way too small, and 2) norm-conserving: increasing the ratio between ecutrho and ecutwfc beyond its standard value 4 is not justified, Paolo On Sat, Nov 7, 2015 at 12:16 AM, Safa Alzaim <safa.alz...@gmail.com> wrote: > Many thanks, Giovanni, for your explanation. Unfortunately, I am still > getting errors. What could be the issue with the code below? I've checked > all the values. > Thanks, > Safa > > &CONTROL > title = anatase1 , > calculation = 'scf' , > restart_mode = 'from_scratch' , > wf_collect = .true. , > outdir = '/home/osboxes/qe/PWgui-5.2.1/' , > wfcdir = '/home/osboxes/qe/PWgui-5.2.1/' , > pseudo_dir = '/home/osboxes/qe/mypseudo/' , > prefix = 'anatasetry1' , > / > &SYSTEM > ibrav = 7, > A = 3.73 , > C = 9.37 , > nat = 6, > ntyp = 2, > ecutwfc = 40 , > ecutrho = 320 , > / > &ELECTRONS > conv_thr = 1.0d-8 , > mixing_mode = 'plain' , > diagonalization = 'david' , > / > ATOMIC_SPECIES > Ti 46.86700 Ti.blyp-sp-hgh.UPF > O 15.99400 O.blyp-hgh.UPF > ATOMIC_POSITIONS crystal > Ti 0.000000000 0.000000000 0.000000000 > Ti 0.000000000 0.500000000 0.250000000 > O 0.000000000 0.000000000 0.208000000 > O 0.000000000 0.000000000 -0.208000000 > O 0.000000000 0.500000000 0.458000000 > O 0.000000000 0.500000000 0.292000000 > K_POINTS automatic > 2 2 1 1 1 1 > > > > > > > > On Thu, Nov 5, 2015 at 9:00 AM, Giovanni Cantele < > giovanni.cant...@spin.cnr.it> wrote: > >> Dear Safa, >> >> the errors you get is because you input the TiO2 anatase primitive unit >> cell, but include also periodic replicas of some atoms, that means that as >> the scf cycle starts, some atoms overlap and it will never converge! >> >> For example: >> Ti 0.000000000 0.000000000 0.000000000 >> and >> Ti 3.730000000 0.000000000 0.000000000 >> are obtained one from the other through a lattice translation (a,0,0) and >> so they cannot be included both in the ATOMIC_POSITIONS card if the A and C >> parameters specify the crystal primitive cell. >> >> If you want to use the cif file with VESTA, before exporting the xyz >> coordinates you must be sure that only the atoms in the primitive cell are >> shown. However, you can also look through lot of papers published >> on TiO2 anatase and related systems. If you do so, you discover that the >> unit cell contains two TiO units with Ti ions at 0,0,0 and (0, 1/2 , 1/4) >> and O ions at (0,0,u), (0,0,-u), (0,1/2 ,u+1/4 ) and (0,1/2 , 1/2-u) with >> u=0.208. >> This coordinates are in crystal units. >> >> >> Giovanni >> >> -- >> >> Giovanni Cantele, PhD >> CNR-SPIN >> c/o Dipartimento di Fisica >> Universita' di Napoli "Federico II" >> Complesso Universitario M. S. Angelo - Ed. 6 >> Via Cintia, I-80126, Napoli, Italy >> e-mail: giovanni.cant...@spin.cnr.it >> Phone: +39 081 676910 >> Skype contact: giocan74 >> >> ResearcherID: http://www.researcherid.com/rid/A-1951-2009 >> Web page: http://people.na.infn.it/~cantele >> >> > On 05 Nov 2015, at 02:43, Safa Alzaim <safa.alz...@gmail.com> wrote: >> > >> > Hello All, >> > I am new at QE, so please excuse the simplicity of my questions. I >> am working with bulk TiO2 anatase. I downloaded a cif, and then used Vesta >> to convert the data to xyz coordinates. However, I get the 31 atom unit >> cell instead of the primitive cell. In any case, I entered A and C values. >> I keep getting errors when I try to run the file. If anybody could help, >> I'd really appreciate it. >> > Thanks! >> > Safa >> > >> > >> > &CONTROL >> > title = anatase1 , >> > calculation = 'scf' , >> > restart_mode = 'from_scratch' , >> > wf_collect = .true. , >> > outdir = '/home/osboxes/qe/PWgui-5.2.1/' , >> > wfcdir = '/home/osboxes/qe/PWgui-5.2.1/' , >> > pseudo_dir = '/home/osboxes/qe/mypseudo/' , >> > prefix = 'anatasetry1' , >> > / >> > &SYSTEM >> > ibrav = 7, >> > A = 3.73 , >> > C = 9.37 , >> > nat = 31, >> > ntyp = 2, >> > ecutwfc = 40 , >> > ecutrho = 320 , >> > / >> > &ELECTRONS >> > conv_thr = 1.0d-8 , >> > mixing_mode = 'plain' , >> > diagonalization = 'david' , >> > / >> > ATOMIC_SPECIES >> > Ti 46.86700 Ti.blyp-sp-hgh.UPF >> > O 15.99400 O.blyp-hgh.UPF >> > ATOMIC_POSITIONS angstrom >> > Ti 0.000000000 0.000000000 0.000000000 >> > Ti 0.000000000 0.000000000 9.370000000 >> > Ti 0.000000000 3.730000000 0.000000000 >> > Ti 0.000000000 3.730000000 9.370000000 >> > Ti 3.730000000 0.000000000 0.000000000 >> > Ti 3.730000000 0.000000000 9.370000000 >> > Ti 3.730000000 3.730000000 0.000000000 >> > Ti 3.730000000 3.730000000 9.370000000 >> > Ti 1.865000000 1.865000000 4.685000000 >> > Ti 0.000000000 1.865000000 2.342500000 >> > Ti 3.730000000 1.865000000 2.342500000 >> > Ti 1.865000000 0.000000000 7.027500000 >> > Ti 1.865000000 3.730000000 7.027500000 >> > O 0.000000000 0.000000000 1.874000000 >> > O 0.000000000 3.730000000 1.874000000 >> > O 3.730000000 0.000000000 1.874000000 >> > O 3.730000000 3.730000000 1.874000000 >> > O 1.865000000 1.865000000 6.559000000 >> > O 0.000000000 1.865000000 4.216500000 >> > O 3.730000000 1.865000000 4.216500000 >> > O 1.865000000 0.000000000 8.901500000 >> > O 1.865000000 3.730000000 8.901500000 >> > O 1.865000000 0.000000000 5.153500000 >> > O 1.865000000 3.730000000 5.153500000 >> > O 0.000000000 1.865000000 0.468500000 >> > O 3.730000000 1.865000000 0.468500000 >> > O 1.865000000 1.865000000 2.811000000 >> > O 0.000000000 0.000000000 7.496000000 >> > O 0.000000000 3.730000000 7.496000000 >> > O 3.730000000 0.000000000 7.496000000 >> > O 3.730000000 3.730000000 7.496000000 >> > K_POINTS automatic >> > 2 2 1 1 1 1 >> > >> > _______________________________________________ >> > Pw_forum mailing list >> > Pw_forum@pwscf.org >> > http://pwscf.org/mailman/listinfo/pw_forum >> >> >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum@pwscf.org >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > _______________________________________________ > 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
anatase.in
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