Thanks for your reply, Mohnish. The 'relax' calculation will keep the volume constant but it will fix the cell parameters, too. For example, if I optimize a tetragonal cell, I want the c and a axis to change but the volume unchanged. I know this could be done by varing c/a ratio manually with a series of relax calculation. My question is, can this be done automatically in QE?
------------------ Kun Yin 2010-05-30 Dear Yin 'vc-relax' calculation optimizes the structures by the lattice parameters also but if you set the calculation 'relax' then it optimizes the geometry within the given fixed volume constraints. This calculation moves the atom keeping the volume constant within the given symmetry constraint. hope this helps :) On Sun, May 30, 2010 at 6:12 PM, Kun Yin <kyin.cn at gmail.com> wrote: > Dear All, > > Does anyone have the experience to do volume fixed optimization with QE, > which means the structure is optimized allowing all cell parameters and > atomic positions to vary while keeping the volume fixed? > > Kun Yin > Najing University, China > 2010-05-30 > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- Regards, MOHNISH, ----------------------------------------------------------------- Mohnish Pandey Y6927262,4th Year dual degree student, Department of Chemical Engineering, IIT KANPUR, UP, INDIA +919235721300 ----------------------------------------------------------------- _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum
