Dear Users,
I am using DMoL3 module in MS4.2 to compute thermodynamic properties of crystal structures (NaCl, Ti, Al etc). For vibrational frequency calculations, I had to break the symmetry to P1 and run the calculations.
Comparing the outputs from the calculations with experimental values, vibrational frequencies, Cp,Enthalpy are in agreement (with slight deviation) but entropy values are overestimated by nearly 60J/molK. This is obvously due to the reduced symmetry.This is affecting my free energy calculations.

I was looking for any correlation between symmetry and entropy that I can use as correction factors for obtained entropies from my calculations. Please let me know if you have any suggestions.

Thanks in Advance,