Faunus::TranslationalEntropy Class Reference

Entropy change due to particle fluctuations. More...

#include <montecarlo.h>

Public Member Functions
	TranslationalEntropy (const Space &trial_space, const Space &space)
double	energy (const Change &change)
	Entropic contribution to MC trial energy. More...

Detailed Description

Entropy change due to particle fluctuations.

Entropic contribution to the change associated with a density fluctuation. This far tested with particle fluctuations, only, i.e. when the number of particles change due to a grand canonical or speciation move.

\[ \beta \Delta U = - \sum \ln ( N_o!/N_n! V^{N_n - N_o} ) \]

The sum runs over all products and reactants for the old (o) and new (n) configurations. The "energy" is not a real energy but merely the logarithm of the bias to be included in the Metropolis criterion, so that it can be added to the potential energy.

Note

Space::findMolecules has O(N) complexity for non-atomic molecules; otherwise constant

Todo:

• [ ] Move to Energy namespace?
• [ ] Verify with volume fluctuations which would make Energy::Isobaric redundant

Member Function Documentation

energy()

double Faunus::TranslationalEntropy::energy

(

const Change &

change

)

Entropic contribution to MC trial energy.

Parameters

change

Change due to latest Monte Carlo move

Returns

Logarithm of the bias for the Metropolis criterion (units of kT)

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The documentation for this class was generated from the following files:

• src/montecarlo.h
• src/montecarlo.cpp