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Re: Pressure used for the thermochemical property calculation

Alex Granovsky

Dear Patrick,

Firefly always uses standard pressure of 101325 Pascal.

If you want to recalculate thermochemical properties at
different pressure, you can do this manually.

You need to take into account that within the approximations
used by Firefly, the only part of statistical sum Q that depends
on the pressure is the translational contribution to Q.
Therefore, only translational contributions to thermodynamic
functions depend on the pressure. You can find the equations
for these dependencies in any textbook on physical chemistry.

Hope this helps.

Kind regards,
Alex Granovsky

On Wed Dec 12 '12 11:49am, Patrick SK Pang wrote
>Dear all,

>In the Hessian calculation, can the pressure used for the determination of the thermochemical properties be changed? If so, how can I do?



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