how to choose a appropriate nose mass

[destine]

the vasp guide say choose the typical phonon frequency,but I don't know what is the typical frequecny,for SODIUM,whether it is the maximum frequency or the center frequency of phonon spectrum , for sodium the maximum frequency of phonon is 4 THz at room temperature ,so what is the best temperature oscillation frequency. another question is if the pressure change ,if we need Chang the nose mass.that is all the problem.