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Questions tagged [entropy]

Questions relating to entropy. The entropy S, of a physical system, is related to the number of possible microscopic configurations of that system. It is also a measure of disorder in a physical system.

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17 votes
4 answers

Are there any open source software for calculating the rotational and translational entropy of molecules?

What is a good open source software for calculating the rotational and translational entropy of molecules? The National Institute of Standards and Technology does not provide standard molar entropy ...
ericwalk's user avatar
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15 votes
1 answer

How to calculate the conformational entropy of a molecule?

Introduction It is know that the entropy of a system can be calculated using the formula (1): \begin{equation} \label{eq:entropy_Boltz} S = {k_B}\ln \Omega\tag1 \end{equation} where $k_B$ is the ...
Camps's user avatar
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12 votes
1 answer

What are the methods for calculating solvation effects in free energies and how do they compare?

I've just found this paper (J. Chem. Phys. 141, 174106 (2014)) that deals with the translational and rotational entropies in solution. The method is promising but, unfortunately, requires a ...
schneiderfelipe's user avatar
12 votes
0 answers

Correlation Functions in the Cluster Variation Method [closed]

I've been referring to Dr Mohri's paper [DOI: 10.1007/s11837-013-0738-5] for the cluster variation method (CVM). I wish to calculate the configurational entropy of a binary FCC system. Cluster ...
Hitanshu Sachania's user avatar
9 votes
1 answer

VASP output energy

Which VASP output energy, after sigma -> 0 or before, do you use when combining with zero point energy and vibrational entropy obtained via vtst tools? (Vtst tools provide the vibrational frequencies ...
ericwalk's user avatar
  • 269
9 votes
1 answer

Rigorous definition of electronic entropy

Suppose we want to compute the exact standard molar electronic entropy of helium at a finite but not very high temperature, say $T = 298.15 \textrm{ K}$. By "standard" I mean the standard ...
wzkchem5's user avatar
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7 votes
2 answers

Computing the rotational entropy in RRHO approximation

I am implementing the computation of Gibbs energies by their molecular parameters (structure, frequencies) in my program Chemcraft (the main task is the possibility to cut small frequencies which ...
Linkey's user avatar
  • 406
6 votes
0 answers

Atomic Packing Fraction [closed]

I need to calculate excess entropy of mixing for a particular system of alloy. The excess entropy of mixing is dependent on temperature and it takes into account this temperature dependence by using ...
Mr.Meta's user avatar
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4 votes
0 answers

Computation of thermodynamic functions of molecules by molecular parameters [closed]

I want to implement in my program Chemcraft the computation of entropy and Gibbs energy of molecules in approximation "rigid rotor - harmonic oscillator", by the molecular parameters (...
Linkey's user avatar
  • 406