Dear all,
I am trying to calculate ΔG of adsorbed species by using VASP. For this I need to calculate Zero point energies and Entropy of absorbed species. But I am confused with that. What type of calculations do I need to get ZPE and Entropy. Please help me in this case.
Thanks in advance.
anjibabu
Dear Anji all these energetics quantities are relative quantities in classical mechanics and thermodynamics one can only measure their changes while they go from one state to another. The other interesting point these changes don't depend on the way or better to say the path they follow up to reach the given state. The mostly we take the room temperature and standard atmospheric pressure as reference state to define the chemical potentials of each species. Don't forget the specific Gibbs free energy for a multi-component system is equal to the some of the bi- products of individual chemical potential by their mole fractions. g =SUM x k ChemPotentialk
Dear Anji,
I think that you particularly want to deal with the entropy of the adsorbed species. In M. Sassi, et al. ChemPhysChem 2009, 10, 2480-2485, we used a simple model where adsorbed species had lower (or even canceled) translational and rotational contributions.
regards
Dear Anji, All these prototype shortwaves no matter how sophisticated they are, one would have heal of a time to adapt them to the specific problems one faces in materials science. Because of that I have always developed my own tailor made codes in first MatCad environment and then switch to FORTRAN, including the mathematical subroutines even though some of them are available in IMSL etc.
One easily organize
Entropy: A concept that is not a physical quantity
https://www.researchgate.net/publication/230554936_Entropy_A_concept_that_is_not_a_physical_quantity
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