Hi Kostya, Thanks for your response, it was very helpful.
Veronica El lun, 07-04-2008 a las 13:30 -0700, Konstantin Kudin escribi?: > Hi Veronica, > > The CP code only requires the frequency of the thermostat in THz, and > Doc/INPUT.HOWTO is not applicable in this case. > > As a rough guidance, 3 terahertz = 100 cm^-1 . > > So, suppose you are simulating heavy water where low frequencies are > around 200 cm^-1, and high frequencies near 2500 cm^-1. Then thermostat > frequency could be around 800 cm^-1, resulting in "fnosep=24.0" for the > CP code. > > You could also use chains, and make frequencies in the chain vary. > Then you can set: > nhpcl = 4 > fnosep = 12.0 9.0 6.0 3.0 > and you'll have a chain of thermostats with 400, 300, 200, 100 cm^-1. > > I hope this helps a bit. > > Kostya > > > Kostya > > --- Veronica Muriel Sanchez <vero at qi.fcen.uba.ar> wrote: > > > Hello, > > > > My name is Veronica Sanchez, I'm doing my PhD study on material > > science. > > I want to perform a dynamic calculation using the Nose-Hoover > > thermostat > > implemented in the Quantum Espresso code, using a Car-Parinello > > dynamic. > > > > I read your question (and the answer) in the PWscf forum. I have the > > same question as you did. You wrote this: > > > > > > "(2) fnosep > > As mentioned in the Doc/input_CP, fnosep means the oscillation > > freq. of > > the nose thermostat. While in the Doc/INPUT.HOWTO, I was told > > QNP=2*g*Kb/Omega^2, where Omega is the typical ionic frequency. Dose > > fnosep > > and Omega represent the same thing?" > > > > I know from the answer that is not the same, but I still don't know > > how to determine the fnosep parameter. > > If you have understood how to do it, I will be very greatful if you > > can help me. > > > > Thanks in advanced, > > Best regards, > > > > Ver?nica S?nchez > > > > _______________________________________________ > > Pw_forum mailing list > > Pw_forum at pwscf.org > > http://www.democritos.it/mailman/listinfo/pw_forum > > > > > > > ____________________________________________________________________________________ > You rock. That's why Blockbuster's offering you one month of Blockbuster > Total Access, No Cost. > http://tc.deals.yahoo.com/tc/blockbuster/text5.com > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum >
