On Tue, 15 Jul 2008, Mansoureh Pashangpour wrote: MP> Dear Axle MP> At first I wanted to use CP molecular dynamics for my system but after that MP> I found I couden't use it for metalic systems.so I must use born-oppenhiemer MP> molecular dynamics.I think it needs to minmization like CP MD.do you think MP> different?
what you have to do or not is not a matter of my opinion, but of the requirements of the physics of your system (which is ?), the accuracy of the results you want to achieve and the effort you want to invest. please have a look at what is done to the wavefunction in CP dynamics and what is done in BO dynamics instead then you can answer this for yourself. this something you should know _before_ starting _any_ of those calculations. for example the review by dominik marx and juerg hutter (listed on the QE homepage somewhere under "learn") gives a good overview (it is a bit dated by now, there have been significant improvements, particularly in BO-dynamics since). cheers, axel. MP> good luck MP> Mansoureh MP> MP> On 7/15/08, Axel Kohlmeyer <akohlmey at cmm.chem.upenn.edu> wrote: MP> > MP> > On Tue, 15 Jul 2008, Mansoureh Pashangpour wrote: MP> > MP> > MP> Deal PWscf users MP> > MP> MP> > MP> I want to do minimization for Born-Oppenhiemer molecular dynamics. MP> > MP> which of these way is correct? MP> > MP> > please explain. what is "minimization for BO dynamics"? MP> > MP> > MP> > both your input fragments don't make much sense as they MP> > contain too little information... MP> > MP> > cheers, MP> > axel. MP> > MP> > MP> MP> > MP> dt =6.0d0, MP> > MP> . MP> > MP> . MP> > MP> . MP> > MP> &electrons MP> > MP> emass = 500.d0, MP> > MP> emass_cutoff = 2.25d0, MP> > MP> orthogonalization = 'ortho', MP> > MP> electron_dynamics = 'damp', MP> > MP> / MP> > MP> &ions MP> > MP> ion_dynamics = 'none', MP> > MP> / MP> > MP> --------------------------------- MP> > MP> dt =20.0d0, MP> > MP> . MP> > MP> . MP> > MP> . MP> > MP> &electrons MP> > MP> emass = 500.d0, MP> > MP> emass_cutoff = 2.25d0, MP> > MP> orthogonalization = 'ortho', MP> > MP> electron_dynamics = 'cg', MP> > MP> / MP> > MP> &ions MP> > MP> ion_dynamics = 'none', MP> > MP> / MP> > MP> ---------------------------------- MP> > MP> I look forward to hearing from you. MP> > MP> Thanks MP> > MP> Mansoureh MP> > MP> MP> > MP> > -- MP> > ======================================================================= MP> > Axel Kohlmeyer akohlmey at cmm.chem.upenn.edu http://www.cmm.upenn.edu MP> > Center for Molecular Modeling -- University of Pennsylvania MP> > Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323 MP> > tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425 MP> > ======================================================================= MP> > If you make something idiot-proof, the universe creates a better idiot. MP> > _______________________________________________ MP> > Pw_forum mailing list MP> > Pw_forum at pwscf.org MP> > http://www.democritos.it/mailman/listinfo/pw_forum MP> > MP> -- ======================================================================= Axel Kohlmeyer akohlmey at cmm.chem.upenn.edu http://www.cmm.upenn.edu Center for Molecular Modeling -- University of Pennsylvania Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323 tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425 ======================================================================= If you make something idiot-proof, the universe creates a better idiot.
