I was told that when MD.VariableCell is setted True, then we can not use block kgrid_Monkhorst_Pack option . Thanks very much .
2014-07-21 15:31 GMT+08:00 Максим Арсентьев <[email protected]>: > You right, you should perform 2 structural relaxations. Before doing this > do calculations without geom. optim. with different density of kpoints by > "%block kgrid_Monkhorst_Pack" and see convergence of kpoint density on > forces. This also should be checked for meshcutoff - convergence in forces > is very important for geom. optim. > > > 2014-07-21 6:59 GMT+04:00 邵德喜 <[email protected]>: > > Thanks very much. >> Do you mean that I should do structual relaxation twice?First with >> MD.VariableCell >> False,then with MD.VariableCell True? >> If I could just do structual relaxation once with MD.VariableCell True? >> And if " kgrid Monkhorst Pack" option can be reserved at the same time >> ? >> Yours Sincerely! >> Dexishao >> >> >> 2014-07-21 4:55 GMT+08:00 Максим Арсентьев <[email protected]>: >> >> Dear, Dexi! >>> >>> You can vary residual strain by MD.MaxStressTol. >>> Use CG, relax with MD.VariableCell False first, then input coordinates >>> obtained to a new file with MD.VariableCell True. >>> Note you may need to shift some atoms manually before geometry >>> optimization: if all atoms are in 2D plane, then all of them will remain in >>> plane after geom. optim. because z forces are zero, so you need to shift >>> any atom to unlock z forces and avoid such a false state. >>> >>> >>> 2014-07-20 4:01 GMT+04:00 邵德喜 <[email protected]>: >>> >>> Dear everyone: >>>> I really want to know how to get a structure wuthout strain.For example >>>> ,Let's consider graphene ,I get the structure from materials studio,and use >>>> it as initial one for siesta structual relaxation. >>>> If in the relaxation set some options as follows: >>>> MD.TypeOfRun CG/Verlet >>>> MD.VariableCell True >>>> ... >>>> At the same time ,I replace " kgrid Monkhorst Pack" option with k-grid >>>> cutoff. >>>> When the relaxation is done,I want to ask if the final structure after >>>> relaxation is >>>> one structure without strain? >>>> In general ,how to get a structure without strain is what I care. >>>> Thanks in advance. >>>> Dexi Shao >>>> >>> >>> >>> >>> -- >>> Best wishes, >>> Maxim Arsent'ev, D.Sc.(Chemistry) >>> Laboratory of research of nanostructures >>> Institute of Silicate Chemistry of RAS >>> >> >> > > > -- > Best wishes, > Maxim Arsent'ev, D.Sc.(Chemistry) > Laboratory of research of nanostructures > Institute of Silicate Chemistry of RAS >
