Dear Abolore, Read this article it contains all the atomic positions for the compound. You need to know that for this compound Z=8.
http://www.springerlink.com/content/p27870432mt31374/fulltext.pdf ? Adetunji Bamidele Ibrahim(PhD Student) Department of physics,University of Agriculture, Abeokuta, Ogun State,Nigeria. ________________________________ From: Abolore Musari <abmus007 at gmail.com> To: PWSCF Forum <pw_forum at pwscf.org> Sent: Monday, August 6, 2012 4:42 PM Subject: Re: [Pw_forum] equilibrium lattice constant of magnetite Thanks so much Jia But Sir the atomic positions in the input is for 3 atoms, should l leave the atomic position and change the number of atom or my atomic position is wrong?? thanks Musari A. A UNAAB Nigeria On Mon, Aug 6, 2012 at 3:34 PM, jia chen <jiachen at princeton.edu> wrote: Dear Abolore Musari, > > >I guess the number of atoms should be 14, instead of 3. > > >Regards >Jia > > >On Mon, Aug 6, 2012 at 10:24 AM, Abolore Musari <abmus007 at gmail.com> wrote: > >Dear QE users >>Sir, I am try to find the lattice constant of magnetite (Fe3O4) which is a >>spinel ferrimagnetic material. The expt lattice constant was 15.87 and I have >>been trying to find the equilibrium lattice constant (celldm(1)) between >>15.80 - 16.00 and all i get is a straight line graph instead of the usual >>exponential curve graph. I have tried all l could most esp with >>starting_magnetization but the results are the same. My input is pasted below >>pls help me to get the appropriate graph. >>The kind of the graph I got is attached. >>Thanks >> >>&control >>??? calculation = 'scf', >>??? restart_mode ='from_scratch', >>??? prefix = 'Fe3O4', >>??? pseudo_dir = '/home/abolore/Programs/Pseudos/', >>??? outdir = './tmp/' >>?/ >>?&system >>??? ibrav = 2, >>??? celldm(1)= $15.80-16.00, >>??? nat = 3, >>??? ntyp = 3, >>??? ecutwfc = 40, >>??? ecutrho = 400, >>??? starting_magnetization(1) = 0.7, >>??? starting_magnetization(2) = -0.5, >>??? starting_magnetization(3) = 0.0, >>??? nspin = 2, >>??? occupations='smearing', >>??? smearing='gaussian', >>??? degauss = 0.05, >>?/ >>?&electrons >>?? diagonalization = 'david', >>?? mixing_mode = 'plain', >>?? mixing_beta = 0.7 >>?/ >>ATOMIC_SPECIES >>??? Fe1???? 55.845?? Fe.pz-nd-rrkjus.UPF >>??? Fe2??? ?55.845??? ? Fe.pz-nd-rrkjus.UPF >>???? O????? 16.000??? ? O.pz-rrkjus.UPF >> >>ATOMIC_POSITIONS >>Fe1 0.125? 0.125? 0.125? >>Fe2 0.500? 0.500? 0.500 >>O??? 0.2548 0.2548 0.2548 >>? >>K_POINTS (automatic) >>? 8 8 8 1 1 1 >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >> >>_______________________________________________ >>Pw_forum mailing list >>Pw_forum at pwscf.org >>http://www.democritos.it/mailman/listinfo/pw_forum >> >> > > > >-- >Jia Chen > > > >_______________________________________________ >Pw_forum mailing list >Pw_forum at pwscf.org >http://www.democritos.it/mailman/listinfo/pw_forum > > _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120806/3e3c6170/attachment.htm
