Rapid calculation of partition functions and free energies of fluids.
J Chem Phys
; 135(17): 174105, 2011 Nov 07.
Article
em En
| MEDLINE
| ID: mdl-22070290
ABSTRACT
The partition function (Q) is a central quantity in statistical mechanics. All the thermodynamic properties can be derived from it. Here we show how the partition function of fluids can be calculated directly from simulations; this allows us to obtain the Helmholtz free energy (F) via F = -k(B)T ln Q. In our approach, we divide the density of states, assigning half of the configurations found in a simulation to a high-energy partition and half to a low-energy partition. By recursively dividing the low-energy partition into halves, we map out the complete density of states for a continuous system. The result allows free energy to be calculated directly as a function of temperature. We illustrate our method in the context of the free energy of water.
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Base de dados:
MEDLINE
Assunto principal:
Água
/
Simulação de Dinâmica Molecular
Idioma:
En
Revista:
J Chem Phys
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Reino Unido