The only way to achieve what you like is to modify the code. See "init_dofree" in Modules/cell_base.f90. Note that if you impose a constraint, you have to ensure that it doesn't break some symmetry that is present in the initial state
Paolo On Mon, May 30, 2016 at 12:49 PM, Francesco Macheda <[email protected]> wrote: > Hi everybody, > I need a little help about cell_dofree type optimization. This is part of my > input : > > ATOMIC_POSITIONS crystal > Ge 0.00E+00 0.50E+00 0.75E+00 0 0 0 > Ge 0.50E+00 0.00E+00 0.25E+00 0 0 0 > Ge 0.00E+00 0.00E+00 0.00E+00 0 0 0 > Ge 0.50E+00 0.50E+00 0.50E+00 0 0 0 > CELL_PARAMETERS angstrom > 2.825 2.825 0.0 > 2.6 2.6 0.0 > 0.0 0.0 5.65 > > Now, i've seen all the cell_dofree options but I would like to make a > vc-relax such that THE ENTIRE v_2 lattice vector is kept fixed whereas the > other two vectors are free to move, and I've not found it possible by > cell_dofree (only to fix the components can be choosen). > > I know that a possible solution is to rotate the crystal and then use > cell_dofree on the cartesian components, but I would prefer to find a direct > solution, if possible, because otherwise I would have to change a lot of > other inputs. > Thank you in advance, > Francesco Macheda > Graduating student at Pisa University > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, 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
