Dear Dr Dubbeldam,

according to the RASPA output in NPT-MC simulations, the formula

related to the enthalpy fluctuations is used to calculate the isobaric heat capacity Cp:

[1/(kB T^2)]*[<H^2>-<H>^2]

The results are expressed in the output as [J/mol/K.]

However, my question is if these values need to be divided by the number of molecules in

the NPT simulation to get the correct values, since this seems to be the case.

Is this correct?

Your answer will be highly appreciated.

PS: Note also that in the case of Monte Carlo, only the configurational enthalpy is taken into account. Therefore,

the value of the isobaric heat capacity calculated with RASPA corresponds to the configurational Cp.

In order to calculate the overall isobaric heat capacity Cp, the kinetic energy contributions need to be taken into account

as well. There are several ways to do so, which are already presented in the literature, e.g.

M. Lagache, P. Ungerer, A. Boutin, A. H. Fuchs, Prediction of thermodynamic derivative properties of fluids by Monte Carlo simulation, Phys.Chem.Chem.Phys., 2001,3, 4333-4339