<div dir="ltr"><span style="font-size:12.8000001907349px">Hi all,</span><div style="font-size:12.8000001907349px">I've been running a vc_relax calculation on a 40 atom system. The calculation works fine for some cycles. The total force had come down to 0.108. After some time.<span style="font-size:12.8000001907349px"> the force started increasing and now the iterations don't converge even in 400 steps. The input file is</span></div><div style=""><div style=""><span style="font-size:12.8000001907349px"> /</span><br></div><div style=""><span style="font-size:12.8000001907349px"> &SYSTEM</span></div><div style=""><span style="font-size:12.8000001907349px">                       ibrav = 0,</span></div><div style=""><span style="font-size:12.8000001907349px">                         nat = 40,</span></div><div style=""><span style="font-size:12.8000001907349px">                        ntyp = 1,</span></div><div style=""><span style="font-size:12.8000001907349px">                     ecutwfc = 12 ,</span></div><div style=""><span style="font-size:12.8000001907349px"> /</span></div><div style=""><span style="font-size:12.8000001907349px"> &ELECTRONS</span></div><div style=""><span style="font-size:12.8000001907349px">                 mixing_beta = 0.3 ,</span></div><div style=""><span style="font-size:12.8000001907349px">             diagonalization = 'david' ,</span></div><div style=""><span style="font-size:12.8000001907349px">             electron_maxstep = 200 ,</span></div><div style=""><span style="font-size:12.8000001907349px"> /</span></div><div style=""><span style="font-size:12.8000001907349px"><br></span></div><div style=""><span style="font-size:12.8000001907349px">[&Ions/]</span></div><div style=""><span style="font-size:12.8000001907349px">/</span></div><div style=""><span style="font-size:12.8000001907349px">&CELL</span></div><div style=""><span style="font-size:12.8000001907349px">cell_dynamics= 'sd' ,</span></div><div style=""><span style="font-size:12.8000001907349px">cell_dofree='xy' ,</span></div><div style=""><span style="font-size:12.8000001907349px">/</span></div><div style=""><span style="font-size:12.8000001907349px"><br></span></div><div style=""><span style="font-size:12.8000001907349px">CELL_PARAMETERS angstrom</span></div><div style=""><span style="font-size:12.8000001907349px">    22.265358047804796    0.000000000000000    0.000000000000000</span></div><div style=""><span style="font-size:12.8000001907349px">     0.000000000000000   11.131216979724510    0.000000000000000</span></div><div style=""><span style="font-size:12.8000001907349px">     0.000000000000000    0.000000000000000   10.000000000000000</span></div><div style="font-size:12.8000001907349px"><br></div></div><div style="font-size:12.8000001907349px"><div>P.S. Ive tried changing cell dynamics to 'damp-pr' , 'sd' and 'damp-w', but the same problem persists.</div><div>Can anybody Please help me identifying the mistake ?</div><div>Thank You.</div><div>Best Regards,</div><div><div style="font-size:12.8px">Vishal Gupta</div><div style="font-size:12.8px"><p class="MsoNormal" style="font-size:12.8px"><span style="color:rgb(0,0,0);font-size:12.8px">B.Tech. 3rd year Mechanical</span></p><div style="font-size:12.8px;color:rgb(136,136,136)"><span style="font-size:12.8px"><font color="#000000">Indian Institute of Technology Ropar</font></span></div><div style="font-size:12.8px;color:rgb(136,136,136)"><span style="font-size:12.8px"><font color="#000000">Rupnagar (140001), Punjab, India.</font></span></div><div style="font-size:12.8px;color:rgb(136,136,136)"><span style="font-size:12.8px"><font color="#000000">Email :- <a href="mailto:vishal.gupta@iitrpr.ac.in" target="_blank">vishal.gupta@iitrpr.ac.in</a></font></span></div><div style="font-size:12.8px;color:rgb(136,136,136)"><a href="https://sites.google.com/a/iitrpr.ac.in/ropar-mechanics-of-materials-laboratory/people" target="_blank" style="font-family:Calibri,sans-serif;font-size:11pt;line-height:16.8667px">RMML, IIT Ropar</a></div></div></div></div><br><br><br><img width="0" height="0" class="mailtrack-img" src="https://mailtrack.io/trace/mail/487a748cedfb942f92401d52262f336d11784524388949.png"></div>