hyello25 Qgrui wrote: > (1) ion_nstep
"ion_nstepe". Used only for dynamics on the Born-Oppenheimer surface, i.e. with electrons on the ground state. It is not used for the Car-Parrinello dynamics. I am not even sure it is really used > 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? you are answering your own question: no. > If a system was calculated with the phonon frequency at Gamma point, > such as 100cm^-1, 200cm^-1, 500cm^-1 respective, How should I set the > fnosep? is fnosep=7.5 ok, because of 3 THz=100cm^-1 and Omega should be > half of the maximum phonon freq? the best way to know is to try > In the SYSTEM namelist, > (3)ecfixed, qcutz, q2sigma > What is the general value we often use in vc-MD process? I think > this question is stupid, these parameters value may come from > experience. While how can I know, the value I set is ok or bad? some explanation here: http://www.quantum-espresso.org/wiki/index.php/Methodological_Background#Stress P. -- Paolo Giannozzi, Democritos and University of Udine, Italy
