Hi Lorenzo, thank you very much for your comment, I do appreciate it and it does help!
Fixing this is not a problem. I already did it VASP-style, which requires compiling a separate binary for every particular cell-relaxation constraint. Granted, this is much less elegant than using the "cell_dofree" switch but it gets the job done. BTW, I have a tiny and very conservative example that I used to study the "cell_dofree" functionality, which converges in around 20 damped-dynamics steps (and then sits around doing nothing until the limit of ionic steps is reached). I can send it to you privately if you are interested and willing to play with it. Cheers, Serge Lorenzo Paulatto wrote: > Serge Nakhmanson ha scritto: >> Dear All, >> >> Is "cell_dofree" feature in &CELL completely implemented >> in Espresso 4.0.x? > Dear Serge, > I can't give you a definitive answer, as I haven't really used this > feature. What I can say is that it is not implemented with bfgs > algorithm and even with damp I'm not really sure it is working. I tried > to find a quick fix some time ago, but had to give up due to other work. > >> condition in vcsmd.f90 is never reached. Or am I missing >> something? >> > I think you are right, but it is easy to fix, change > ABS( sigma(i,j) ) * uakbar > to > ABS( sigma(i,j) ) * iforceh(i,j) * uakbar > in both places (be careful with the indexes), and it *should* work. > > I say "should" because I have done a few tries, but couldn't make it > converge; it is probably due to my inexperience with damped dynamics. > >> Would appreciate any sage comments on this. >> > I''m not really a sage, I hope it helped > > bye > -- ********************************************************* Serge M. Nakhmanson phone: (630) 252-5205 Assistant Scientist fax: (630) 252-4798 MSD-212, Rm. C-224 Argonne National Laboratory 9700 S. Cass Ave. Argonne, IL 60439 *********************************************************
