Dear Bhamu, you better use two different kinds for the Fe in octahedral sites: one for 2+ the other for 3+. they are likely to have different U's as well.
Matteo Il giorno mer 1 dic 2021 alle ore 11:34 Dr. K. C. Bhamu <[email protected]> ha scritto: > Dear Dr. Matteo, > > Thank you very much for the quick response. > > Yes, I am doing vc-relax in between each step. Doing vc-relax without > adopting geometry information from the previous run. I am only supplying > the HP file containing U+V obtained from the previous run for the vc-relax > for the next step. > > Fe1 (octahedral coordination) atom has a mixed charge state (Fe3+ and > Fe2+). > The magnetic moment of Fe1( Fe3+) cancels out with Fe2 (tetrahedral > coordination; all Fe3+) and the resultant magnetic moment comes from Fe1 > (2+) atoms. > According to Ref. [1] > <https://www.sciencedirect.com/science/article/abs/pii/S0039602812000544>, > I set all Fe1 as up and all Fe2 as down spins. > > Do you think my input still has some issues? > > ------------------- > I am providing some additional information here. > > Additional information: > > Ref. [1] > <https://www.sciencedirect.com/science/article/abs/pii/S0039602812000544> > Just below Fig. 3 it is mentioned that "For Fe3O4 having ferrimagnetic > property, the spin of the octahedral and tetrahedral Fe was set as up and > down, respectively." > > > Relevant para from Ref. [2] > <https://link.springer.com/article/10.1134%2FS1027451010030079> is as > below: > Fe2+ cations in the face-centered cubic lattice formed by oxygen anions > occupy octahedral sites, while Fe3+ cations are distributed between > octahedral and tetrahedral sites. The trivalent Fe3+ ion is in the state > with a spin S = 5/2 and zero orbital moments. The bivalent Fe2+ ion has a > spin of 2, and its contribution comes to ~4μB unless one considers a > certain possible contribution from the orbital moment [2]. The measured > value of the magnetic moment for magnetite is 4.1μB. The magnetic moments > of Fe3+ ions are antiparallel to each other, and the observed moment is > determined by Fe2+ ions only (Fig. 1). > > > Thanks and regards > Bhamu > > > > On Wed, Dec 1, 2021 at 2:17 PM Matteo Cococcioni < > [email protected]> wrote: > >> the fourth iteration does not look too good to me as the U for Fe2 is >> suddenly going from 4.31 to 0.7. >> Fe3O4 is a difficult system of its own. are you sure that all the Fe1 are >> of the same kind (3+)? The system is for sure >> a mixed valence one but I don't remember how this matches its magnetic >> structure. Are you relaxing the structure in between? >> Maybe because of the structure changes hp is not recognizing the >> neighbors it had before for each Fe. >> >> Regards, >> >> Matteo >> >> Il giorno mer 1 dic 2021 alle ore 06:07 Dr. K. C. Bhamu < >> [email protected]> ha scritto: >> >>> Dear Iurii, >>> This is from the calculation without nbnd in QE input file (QE input and >>> HP input are supplied at the end of this email). >>> I am trying to get a converged value of U+V. Up to four steps, all the >>> calculations seem to be fine (other than the converged value of U+V). But >>> in the 5th step, I see that my calculations are not converging. >>> >>> I am getting this message: >>> atom # 5 q point # 3 iter # 180 >>> chi: 1 -83.8242814567 residue: 103.6191835332 >>> chi: 2 -83.8242814548 residue: 103.6191835384 >>> chi: 3 ************** residue: 381.0626501229 >>> chi: 4 ************** residue: 326.7198566114 >>> chi: 5 317.5473216386 residue: 329.6382092529 >>> chi: 6 ************** residue: 580.5784405595 >>> chi: 7 9.0496504843 residue: 1.9763844786 >>> chi: 8 -6.2884312048 residue: 21.8495062869 >>> chi: 9 9.0496505082 residue: 1.9763845088 >>> chi: 10 -6.2884312084 residue: 21.8495062832 >>> chi: 11 10.2338160751 residue: 7.3557134894 >>> chi: 12 -5.1687829951 residue: 22.9825921172 >>> chi: 13 6.7503553298 residue: 7.1360232476 >>> chi: 14 -3.9982889995 residue: 27.0388948104 >>> Average number of iter. to solve lin. system: 23.6 >>> Total CPU time : 63284.6 s >>> ################### >>> atom # 5 q point # 3 iter # 274 >>> chi: 1 ************** residue: ************** >>> chi: 2 ************** residue: ************** >>> chi: 3 ************** residue: ************** >>> chi: 4 ************** residue: ************** >>> chi: 5 ************** residue: ************** >>> chi: 6 ************** residue: ************** >>> chi: 7 ************** residue: 78.8265104616 >>> chi: 8 190.5140692168 residue: ************** >>> chi: 9 ************** residue: 78.8264974402 >>> chi: 10 190.5140679621 residue: ************** >>> chi: 11 ************** residue: ************** >>> chi: 12 544.1915326984 residue: ************** >>> chi: 13 ************** residue: ************** >>> chi: 14 ************** residue: ************** >>> >>> U+V value from four completed calculations is given below: >>> >>> >>> site n. type label spin new_type new_label Hubbard U (eV) >>> 1 1 Fe1 1 1 Fe1 5.1791 >>> 5 2 Fe2 -1 2 Fe2 5.0962 >>> 7 3 O 0 3 O 7.1203 >>> >>> site n. type label spin new_type new_label Hubbard U (eV) >>> 1 1 Fe1 1 1 Fe1 5.6013 >>> 5 2 Fe2 -1 2 Fe2 4.3164 >>> 7 3 O 0 3 O 7.5401 >>> >>> site n. type label spin new_type new_label Hubbard U (eV) >>> 1 1 Fe1 1 1 Fe1 5.6013 >>> 5 2 Fe2 -1 2 Fe2 4.3164 >>> 7 3 O 0 3 O 7.5401 >>> >>> site n. type label spin new_type new_label Hubbard U (eV) >>> 1 1 Fe1 1 1 Fe1 4.4843 >>> 5 2 Fe2 -1 2 Fe2 0.7259 >>> 7 3 O 0 3 O 7.3480 >>> >>> >>> I do not think changing "conv_thr_chi" will help here as the number is >>> still oscillating in integer values. >>> >>> What suggestions do you have for this situation? >>> >>> >>> HP input file: >>> >>> &inputhp >>> prefix = 'pwscf', >>> niter_max=300 >>> outdir = './temp/', >>> nq1 = 2, nq2 = 2, nq3 = 2, >>> conv_thr_chi = 1.0d-5, >>> find_atpert = 1 >>> docc_thr=1.d-3 >>> !disable_type_analysis=.true., >>> / >>> >>> QE input file: >>> &CONTROL >>> calculation = 'vc-relax' >>> restart_mode='from_scratch', >>> etot_conv_thr = 1.4000000000d-04 >>> forc_conv_thr = 1.0000000000d-04 >>> outdir = './temp/' >>> prefix = 'pwscf' >>> pseudo_dir = '~/PPs/jana_2/' >>> tprnfor = .true. >>> tstress = .true. >>> verbosity = 'high' >>> / >>> &SYSTEM >>> degauss = 0.022 >>> ecutrho = 320 >>> ecutwfc = 40 >>> occupations = 'smearing' , smearing = 'mp' >>> ibrav = 0 >>> nat = 14 >>> nosym = .false. >>> ntyp = 3 >>> nspin=2 >>> starting_magnetization(1) = 0.8 >>> starting_magnetization(2) = -0.8 >>> starting_magnetization(3) = 0.0 >>> >>> lda_plus_u = .true., >>> lda_plus_u_kind = 2, >>> U_projection_type = 'ortho-atomic', >>> !Hubbard_V(1,1,1) = 1.d-8 >>> !Hubbard_V(5,5,1) = 1.d-8 >>> !Hubbard_V(7,7,1) = 1.d-8 >>> Hubbard_parameters = 'file' >>> >>> >>> / >>> &ELECTRONS >>> conv_thr = 1.0000000000d-06 >>> electron_maxstep = 400 >>> mixing_beta = 1.5000000000d-01 >>> / >>> &IONS >>> ion_dynamics = 'bfgs' >>> / >>> &CELL >>> / >>> >>> ATOMIC_SPECIES >>> Fe1 55.845 Fe.pbe-nd-rrkjus.UPF >>> Fe2 55.845 Fe.pbe-nd-rrkjus.UPF >>> O 15.9994 O.pbe-rrkjus.UPF >>> ATOMIC_POSITIONS (crystal) >>> Fe1 0.0000000000 -0.0000000000 -0.0000000000 >>> Fe1 0.5000000000 0.0000000000 0.0000000000 >>> Fe1 0.9999999892 0.5000000216 -0.0000000000 >>> Fe1 0.9999999965 0.9999999956 0.5000000115 >>> Fe2 0.3749993721 0.3749993349 0.3750019210 >>> Fe2 0.6250006225 0.6250006532 0.6249981020 >>> O 0.2454868415 0.2454868399 0.2454949640 >>> O 0.7545131845 0.7545131098 0.7545050345 >>> O 0.7635313546 0.2454868399 0.2454949640 >>> O 0.2364686713 0.7545131098 0.7545050345 >>> O 0.2454868307 0.7635313746 0.2454949640 >>> O 0.7545132523 0.2364686217 0.7545050345 >>> O 0.2454908593 0.2454908222 0.7635274591 >>> O 0.7545090629 0.7545091741 0.2364725394 >>> >>> CELL_PARAMETERS (angstrom) >>> 5.944682649 0.000000000 0.000000000 >>> 2.972341325 5.148246192 0.000000000 >>> 2.972341325 1.716082064 4.853885701 >>> >>> K_POINTS automatic >>> 7 7 7 0 0 0 >>> >>> >>> Regards >>> Bhamu >>> >>> _______________________________________________ >>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >>> users mailing list [email protected] >>> https://lists.quantum-espresso.org/mailman/listinfo/users >> >> >> >> -- >> Matteo Cococcioni >> Department of Physics >> University of Pavia >> Via Bassi 6, I-27100 Pavia, Italy >> tel +39-0382-987485 >> e-mail [email protected] <[email protected]> >> _______________________________________________ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >> users mailing list [email protected] >> https://lists.quantum-espresso.org/mailman/listinfo/users > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users -- Matteo Cococcioni Department of Physics University of Pavia Via Bassi 6, I-27100 Pavia, Italy tel +39-0382-987485 e-mail [email protected] <[email protected]>
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