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** Re: How to calculate Gibbs-free energy, enthalpy and entropy change in firefly? **
sanya

sanya@photonics.ru

On Mon Feb 13 '12 8:21am, gensz wrote

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>Hello there, I am confused on how to interpret the output file in firefly, I just want to know that, is the TOTAL ENeRGY in :ENERGY COMPONENTS: for the output file is equal to the Enthalpy?...>since I worked on radicals I can't use runtyp=optimize for mp2, therefore i'll only use energy and it does not give me any information on Gibss-energy, Enthalpy and Entropy...

>

>

>Does the information in the HF calculations giving those reaction energies Gibbs,enthalpy and entropy is used for calculating the change in Gibbs-energy, change in Enthalpy and change in entropy?

>Pls help..I'm really confused.

For thermodynamic functions, you have to calculate hessian (RUNTYP=HESSIAN) for the optimized geometry of your molecule (RUNTYP=OPTIMIZE).

From your attached input files I do not see any radicals: ICHARG=0 MULT=1 and no ROHF is necessary.

Tue Feb 14 '12 1:11am

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