I am trying to calculate bulk modulus of an amorphous polymer by fluctuation properties. I was wondering the effect of the Pdamp (and Tdamp) parameter on the fluctuation and the mean values of Volume (in this case). For a value of Pdamp 1000fs, at a pressure of 0 atmosphere, while the mean value of pressure seems reasonable the variance seems very high(wrt to the mean value). However the values of volume(mean and variance) apparently seems ok, but since the variance of the pressure is very high i was wondering the reliability of my conclusions (of bulk modulus in the particular case). Thanking in advance.