Hello, Mona, The calculation methods are not as same as the original paper although you claimed they were the same. The energy convergence criterion you used was very loose for such a 8-atom cell. Try to improve the convergence accuracy of the energy and forces. If your convergence criterion is too low, the structure may be convergence to a seemingly stable phase and it's not correct. One more comment: because the code in the original paper is not QE, you may test more, e.g. kmesh, conv_thr. In addition, for an insulator with a gap, you can consider using smearing='fixed' to reduce the cost of calculation.
Mona Asadinamin <[email protected]> 于2020年7月13日周一 下午10:15写道： > Dear QE users and developers; > > I have been trying to relax Tenorite (CuO) with monoclinic structure. > During relaxation, *the cell parameters change significantly* and *the > final result is not consistent with the literature*. (Please see TABLE II > in this paper: > https://journals.aps.org/prb/abstract/10.1103/PhysRevB.99.035154) > > I am using the same parameters for my calculations as in the paper; here > is my input: > > > &CONTROL > > calculation='vc-relax', > > outdir='.', > > prefix='pw-paperlike', > > pseudo_dir='/home/ma36813/all_pbe_UPF_v1.5', > > verbosity='high', > > etot_conv_thr=1d-05 > > / > > > &SYSTEM > > ibrav=0, > > celldm(1)=5.4811209354d0, > > nat=8, > > ntyp=3, > > ecutwfc=50, > > ecutrho=500, > > occupations='smearing', > > smearing='mv', > > degauss=0.005d0, > > nspin=2, > > starting_magnetization(1)=0.5, > > starting_magnetization(2)=-0.5, > > vdw_corr='grimme-d3', > > / > > > &ELECTRONS > > conv_thr=1d-08, > > mixing_beta=0.7d0, > > / > > &IONS > > / > > &CELL > > / > > > ATOMIC_SPECIES > > Cu1 63.546000d0 cu_pbe_v1.2.uspp.F.UPF > > Cu2 63.546000d0 cu_pbe_v1.2.uspp.F.UPF > > O 15.999400d0 o_pbe_v1.2.uspp.F.UPF > > > ATOMIC_POSITIONS {crystal} > > Cu1 0.0000000000d0 0.2500000000d0 0.0000000000d0 > > Cu2 0.0000000000d0 0.7500000000d0 0.0000000000d0 > > Cu2 0.5000000000d0 0.0000000000d0 0.5000000000d0 > > Cu1 0.5000000000d0 0.5000000000d0 0.5000000000d0 > > O -0.4184000000d0 0.2092000000d0 0.2500000000d0 > > O -0.4184000000d0 0.7092000000d0 0.2500000000d0 > > O 0.4184000000d0 -0.2092000000d0 0.7500000000d0 > > O 0.4184000000d0 0.2908000000d0 0.7500000000d0 > > > K_POINTS {automatic} > > 5 5 5 1 1 1 > > > CELL_PARAMETERS {alat} > > 0.807399649995d0 -0.590004919630d0 0.000000000000d0 > > 1.614799299990d0 1.180009839261d0 0.000000000000d0 > > -0.293063818044d0 0.000000000000d0 1.743801894963d0 > > > > *Please note that CuO is antiferromagnetic so it requires to have a > supercell twice as large as the unit cell. > > My cell parameters are: > •a=4.2949 Angstrom > • b=4.0316 Angstrom > •c=5.1650 Angstrom > •β= 89.744 degrees > And the other two angles, instead of being 90, are 89.947, 88.396. > > I appreciate any comments or suggestions. > > > > Best regards; > > > Mona Asadi Namin > > Graduate student > > Center for simulational physics > > University of Georgia > > -------------------------------------- > > Email:[email protected] <[email protected]>u <[email protected]> > > Phone: +1-215-906-23-92 > > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users -- ------------------------------------------------------------------------------------------------------------ Yue-Wen FANG, PhD Tokyo Institute of Technology, Japan
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