Dear Christopher You should try to reduce conv_thr in &ELECTRONS, in order to have a more accurate calculation of forces and stress. Try, for instance, with conv_thr = 1.0d-9 (and with a lower mixing_beta, 0.2~0.3 or so, if the electronic calculation does not converge). HTH
Giuseppe Quoting Christopher O'Brien <cjobrien at ncsu.edu>: > Below this is a super-cell of an interface of Cu2O and Ti. The > problem is simply that the forc_conv_thr is not met within 100 > iterations. etot_conv_thr is almost always met first (even > decreasing etot_conv_thr to 1.0d-6). Typically, the force in this > system decreases to ~0.01 Ry/B with a delta F on the same order of > magnitude but fluctuates about this value. This means that I > continually get the warning telling me to reduce the convergence > threshold. Ideally I would like obtain a maximum force of ~1D-4. > Does anyone have any suggestions? I am at a loss. > > Thanks in advance, > Chris O'Brien > > > title = 'Cu2O-Ti-case2' , > calculation = 'vc-relax' , > restart_mode = 'from_scratch' , > wf_collect = .false. , > outdir = './', > wfcdir = './', > pseudo_dir = '/share2/cjobrien/pseudo/', > prefix = 'Cu2OTi', > disk_io = 'low', > verbosity = 'minimal', > tstress = .true., > tprnfor = .true., > forc_conv_thr = 1.0d-4, > etot_conv_thr = 1.0d-5, > / > &SYSTEM > ibrav = 0, > celldm(1) = 8.1878, > nat = 14, > ntyp = 3, > ecutwfc = 30.0 , > ecutrho = 300.0 , > occupations = 'smearing' , > smearing = 'mv' , > degauss = 0.01 , > / > &ELECTRONS > conv_thr = 1.0d-6 , > mixing_beta = 0.7 , > / > &IONS > ion_dynamics = 'bfgs', > / > &CELL > cell_dynamics = 'bfgs', > press = 0.0, > cell_dofree = 'xyz', > / > CELL_PARAMETERS > 0.929429709 0.0 0.0 > 0.0 0.929429709 0.0 > 0.0 0.0 2.924945006 > ATOMIC_SPECIES > Cu 58.70000 Cu.pw91-n-van_ak.UPF > Ti 47.88000 Ti.pw91-nsp-van.UPF > O 16.00000 O.pw91-van_ak.UPF > ATOMIC_POSITIONS alat > Cu 0 0 0 > Cu 0.504691013 0.504691013 0 > Cu 0.484702934 0.019988079 0.553031754 > Cu 0.019988079 0.484702934 0.553031754 > Cu 0.039976158 0.039976158 1.106063508 > Cu 0.464714854 0.464714854 1.106063508 > O 0.252345506 0.252345506 0.285738983 > O 0.024221288 0.024221288 1.544049139 > Ti 0.480469725 0.024221288 1.544049139 > Ti 0.024221288 0.480469725 1.544049139 > Ti 0.484702934 0.484702934 2.015504257 > Ti 0.019988079 0.019988079 2.015504257 > Ti 0.01575487 0.488936142 2.486959376 > Ti 0.488936142 0.01575487 2.486959376 > K_POINTS automatic > 8 8 4 0 0 0 > > =================================================================== > Christopher J. O'Brien > cjobrien at ncsu.edu > https://sites.google.com/a/ncsu.edu/cjobrien/ > > Ph.D. Candidate > Computational Materials Group > Department of Materials Science & Engineering > North Carolina State University > __________________________________________________________________ > Please send all documents in PDF. > For Word documents: Please use the 'Save as PDF' option before sending. > =================================================================== > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > Giuseppe Mattioli ISM-CNR, Italy
