On Mon, 2015-04-13 at 00:16 -0700, Florian Altvater wrote: > did this issue ever get resolved/answered? I would also be very > interested in a solution/explanation of the behavior.
The explanation is available in the part of code that perform the convergence check on forces P. > I also get relaxations where individual forces are higher than the > threshold, without the line stating that "SCF correction compared to > forces is large", in case that would be a reason here. Also happens in > regular "relax" calculations. > > Thanks so much, > Florian > > -- > Florian Brown-Altvater > PhD Candidate > Neaton group > UC Berkeley/LBNL > > Am 08.04.2015 um 12:07 schrieb Tianli Feng: > > > Dear All, > > > > > > I would really appreciate if anyone can help to explain a output in > > relaxing a structure. I used vc-relax to relax a lattice > > with forc_conv_thr set as 1.0D-9. After 44 steps, the results > > converge as following: > > > > > > Forces acting on atoms (Ry/au): > > > > > > atom 1 type 1 force = 0.00000638 0.00000000 > > 0.00000092 > > atom 2 type 1 force = 0.00000602 0.00000000 > > 0.00000671 > > atom 3 type 1 force = -0.00000074 0.00000000 > > 0.00000243 > > atom 4 type 1 force = 0.00000358 0.00000000 > > -0.00000082 > > atom 5 type 2 force = -0.00000821 0.00000000 > > -0.00000732 > > atom 6 type 2 force = -0.00000635 0.00000000 > > -0.00000202 > > atom 7 type 2 force = 0.00000337 0.00000000 > > -0.00000058 > > atom 8 type 2 force = -0.00000406 0.00000000 > > 0.00000068 > > > > > > Total force = 0.000018 Total SCF correction = > > 0.000002 > > SCF correction compared to forces is large: reduce conv_thr to > > get better values > > > > > > bfgs converged in 44 scf cycles and 43 bfgs steps > > (criteria: energy < 1.0E-04, force < 1.0E-09, cell < > > 5.0E-01) > > > > > > The last line says the relaxation converges with force <1.0E-9, but > > I saw the forces acting on each atom are not smaller than 1e-9. Does > > anyone has experience on relaxing a lattice and know what is > > happening? Many thanks!! > > > > > > Sincerely, > > Best wishes, > > Tianli > > ------------ > > Tianli Feng > > Mechanical Engineering, Purdue University > > ---The truth is not what you see, but what it is. > > > > > > _______________________________________________ > > Pw_forum mailing list > > [email protected] > > http://pwscf.org/mailman/listinfo/pw_forum > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
