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
