<div dir="ltr">Dear PWSCF users,<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; I turn on the &#39;tefield&#39; option to relax an isolated slab system in the presence of external electric field. The input file is attached below. I use &#39;bfgs&#39; for the ionic dynamics. However I always got the following error: &#39;bfgs history already reset at previous step&#39;. Why &#39;bfgs&#39; method does not work for this &#39;sawlike&#39; electric field? Shall I change some parameters?<br>
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Thank you very much.<br><br>Hanghui Chen<br>Department of Physics,<br>Yale University<br>&nbsp;<br>&amp;CONTROL<br>&nbsp; calculation=&#39;relax&#39;<br>&nbsp; wf_collect=.true.<br>&nbsp; pseudo_dir = &#39;./psp&#39;<br>&nbsp; outdir=&#39;/home1/hc336/scratch&#39;<br>
&nbsp; wfcdir=&#39;/home1/hc336/scratch&#39;<br>&nbsp; prefix=&#39;STO-efield-r-E0.01&#39;&nbsp; <br>&nbsp; tprnfor = .true.<br>&nbsp; tstress = .true.<br>&nbsp; disk_io=&#39;low&#39;<br>&nbsp; verbosity=&#39;high&#39;<br>&nbsp; dt=80.D0<br>&nbsp; tefield=.true.<br>
/<br>&amp;SYSTEM&nbsp;&nbsp; <br>&nbsp; ibrav=&nbsp; 6<br>&nbsp; celldm(1) = 7.02<br>&nbsp; celldm(3) = 5.0<br>&nbsp; nat=&nbsp; 8<br>&nbsp; ntyp= 3<br>&nbsp; ecutwfc = 30.0<br>&nbsp; ecutrho = 180.0<br>&nbsp; occupations=&#39;smearing&#39;<br>&nbsp; smearing=gauss<br>&nbsp; degauss=0.005<br>
&nbsp; edir=3<br>&nbsp; emaxpos=0.8<br>&nbsp; eopreg=0.2<br>&nbsp; eamp=0.01<br>/<br>&amp;ELECTRONS<br>&nbsp; diagonalization=&#39;david&#39;<br>&nbsp; mixing_beta = 0.7D0<br>&nbsp; diago_david_ndim = 4<br>&nbsp; startingwfc=&#39;atomic&#39;<br>&nbsp; startingpot=&#39;atomic&#39;<br>
&nbsp; conv_thr = 1.0d-8<br>/<br>&amp;IONS<br>&nbsp; ion_dynamics = &#39;bfgs&#39;<br>&nbsp; phase_space = &#39;full&#39;<br>&nbsp; pot_extrapolation = &#39;second_order&#39;<br>&nbsp; wfc_extrapolation = &#39;second_order&#39;<br>/<br>&amp;CELL<br>
&nbsp; cell_dynamics = &#39;damp-w&#39;<br>/<br>ATOMIC_SPECIES<br>&nbsp;Sr&nbsp; 87.62&nbsp;&nbsp; 038-Sr-ca-sp-vgrp.uspp.format.UPF<br>&nbsp;Ti&nbsp; 47.90&nbsp;&nbsp; 022-Ti-ca-sp-vgrp.uspp.format.UPF<br>&nbsp;O&nbsp;&nbsp; 16.00&nbsp;&nbsp; 008-O-ca--vgrp.uspp.format.UPF<br>ATOMIC_POSITIONS alat<br>
&nbsp;Ti 0.50 0.50 0.50<br>&nbsp;O&nbsp; 0.00 0.50 0.50<br>&nbsp;O&nbsp; 0.50 0.00 0.50<br>&nbsp;Sr 0.00 0.00 1.00 <br>&nbsp;O&nbsp; 0.50 0.50 1.00<br>&nbsp;Ti 0.50 0.50 1.50<br>&nbsp;O&nbsp; 0.00 0.50 1.50<br>&nbsp;O&nbsp; 0.50 0.00 1.50<br>K_POINTS {automatic}<br>10 10 1 0 0 0<br></div>