14
votes
Are there any open source software for calculating the rotational and translational entropy of molecules?
ASE: Thermochemistry module
The thermochemistry module of ASE is able to calculate these for you.
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12
votes
Are there any open source software for calculating the rotational and translational entropy of molecules?
Any quantum chemical program should calculate these for you as part of a vibrational calculation. Generally, the vibrational, rotational, and translational entropies will be given.
The critical task ...
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10
votes
How to calculate the conformational entropy of a molecule?
tldr, Extensively sample the potential energy surface of the molecule, then Boltzmann-weight the relative energies. The CREST tool is useful.
Nice to see this question as I'm writing / editing a ...
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9
votes
Are there any open source software for calculating the rotational and translational entropy of molecules?
Psi4 and NWChem
For open source software to perform this task, I can think of Psi4. It's probably the easiest to download/install and get going. It has the usual computational chemistry methods along ...
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8
votes
VASP output energy
Always use the energy after extrapolation back to 0 K. The energy before the extrapolation is just from your smearing method and is a fictitious value.
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6
votes
Computing the rotational entropy in RRHO approximation
The symmetry number is the order (number of symmetry elements) of the rotational subgroup of the molecular point group. I.e. the rotational subgroup of $C_{2v}$ is $C_2$, the rotational subgroup of $...
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5
votes
Computing the rotational entropy in RRHO approximation
The argument "a slightly perturbed benzene molecule has an entropy that differs a lot from the entropy of the equilibrium structure" does not hold, because entropies are only defined for ...
- 9,076
5
votes
Accepted
Rigorous definition of electronic entropy
I'll try to summarize the argument mentioned in the comments from Daniel Schroeder's Introduction to Thermal Physics.
Your derivation is correct within a certain approximation commonly made when ...
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5
votes
Are there any open source software for calculating the rotational and translational entropy of molecules?
GoodVibes
GoodVibes is able to calculate what you want from Gaussian logfiles. From its documentation (using scaled vibrational frequencies):
...
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4
votes
What are the methods for calculating solvation effects in free energies and how do they compare?
Just throwing a couple of ideas out there:
(i) Perform a free energy perturbation or potential of mean force calculation as available in typical classical MD setups. For known salt systems in water, ...
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