Dear Stephen; You might want to try a smaller mixing_beta. The default is 0.7.
Best regards; Mona Asadi Namin Graduate student Center for simulational physics University of Georgia -------------------------------------- Email:[email protected]<mailto:[email protected]>u<mailto:[email protected]> ________________________________ From: users <[email protected]> on behalf of Stephen Zhang <[email protected]> Sent: Thursday, July 16, 2020 4:01 AM To: Quantum ESPRESSO users Forum <[email protected]> Subject: [QE-users] Non-converging vc-relaxation calculation [EXTERNAL SENDER - PROCEED CAUTIOUSLY] Hi everyone, I've encountered the issue of my vc-relax calculation not converging. Here is my input, ############################################################ &control calculation = 'vc-relax' prefix = 'CoSnS' outdir = './outdir' pseudo_dir = '/home/stephen/qe-6.5/SSSP_precision_pseudos' etot_conv_thr = 1e-6 forc_conv_thr = 1e-5 / &system ibrav=5, celldm(1) =10.16896836537393, celldm(4) = 0.4980629252775897, nat=7, ntyp=7, ecutwfc=50, ecutwfc=500, occupations='smearing',smearing='gaussian',degauss=0.1, nspin=2, starting_magnetization(1) = 0.24, starting_magnetization(2) = 0.25, starting_magnetization(3) = 0.3, starting_magnetization(4) = 0.02, starting_magnetization(5) = 0.04, starting_magnetization(6) = 0.09, starting_magnetization(7) = 0.01, / &electrons conv_thr=1e-9 / &ions / &cell cell_dofree='ibrav' / ATOMIC_SPECIES Co1 58.933195 Co.pbe-spn-kjpaw_psl.0.3.1.UPF Co2 58.933195 Co.pbe-spn-kjpaw_psl.0.3.1.UPF Co3 58.933195 Co.pbe-spn-kjpaw_psl.0.3.1.UPF Sn4 118.71 Sn.pbe-dn-kjpaw_psl.1.0.0.UPF Sn5 118.71 Sn.pbe-dn-kjpaw_psl.1.0.0.UPF S6 32.065 S.pbe-n-kjpaw_psl.1.0.0.UPF S7 32.065 S.pbe-n-kjpaw_psl.1.0.0.UPF ATOMIC_POSITIONS {crystal_b} Co1 0.5000 0.0000 0.0000 Co2 0.0000 0.5000 0.0000 Co3 0.0000 0.0000 0.5000 Sn4 0.5000 0.5000 0.5000 Sn5 0.0000 0.0000 0.0000 S6 0.7195 0.7195 0.7195 S7 0.2805 0.2805 0.2805 K_POINTS (automatic) 3 3 3 0 0 0 #####################################################################3 A recurring problem I've seen is that the scf accuracy will decrease to a certain point and then jump up again. According to the pw_user_guide<https://www.quantum-espresso.org/Doc/pw_user_guide.pdf> this is due to the fact that I am using few k-points and have a metallic material. The guide recommends the following: Usually one can solve the problem by adding a few empty bands and a small broadening However, I'm not sure on how to do either. Do i just increase the nbnd number and increase the degauss value? Thank you, Stephen -- University of California, Berkeley Department of Letter and Sciences
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