Test area method - Revision history

Carl McBride: Slight correction of the equation.

2009-05-11T15:21:43Z

Slight correction of the equation.

← Older revision		Revision as of 17:21, 11 May 2009
Line 1:		Line 1:
	The '''test area method''' is related to the [[test volume method]] for the calculation of the [[pressure]] (which, in turn, is related to [[Widom test-particle method]]). The [[surface tension]] of a planar [[interface]] is given by the change in [[internal energy]] <math>\Delta U</math> caused by "squeezing" the system: modifying both the length in the direction normal to the interface and the area in the plane of the interface, in such a way that the total volume is left unchanged.		The '''test area method''' is related to the [[test volume method]] for the calculation of the [[pressure]] (which, in turn, is related to [[Widom test-particle method]]). The [[surface tension]] of a planar [[interface]] is given by the change in [[internal energy]] <math>\Delta U</math> caused by "squeezing" the system: modifying both the length in the direction normal to the interface and the area in the plane of the interface, in such a way that the total volume is left unchanged.

	It can be shown that the surface tension, if the changes are small, is given by:		It can be shown that the surface tension, if the changes are small, is given by
	:<~~math~~> ~~\gamma =~~ - ~~\frac{ k_B T \Delta A } \log\langle \exp~~(~~-\Delta U/k_B T~~)~~\rangle.~~ </~~math~~>		<ref>[http://dx.doi.org/10.1063/1.2038827 Guy J. Gloor, George Jackson, Felipe J. Blas and Enrique de Miguel "Test-area simulation method for the direct determination of the interfacial tension of systems with continuous or discontinuous potentials", Journal of Chemical Physics '''123''' 134703 (2005)]</ref> (Eq. 60):

	~~The expression parallels the one for the pressure in the [[test volume method]]; the advantages of this technique are also similar~~: ~~avoidance of force calculation, easiness for discontinuous potential..~~.		:<math> \gamma = - \frac{ k_B T }{ \Delta {\mathcal A} } \ln \langle \exp(-\Delta U/k_B T)\rangle_0. </math>

			The expression parallels the one for the pressure in the [[test volume method]]; the advantages of this technique are also similar: avoidance of force calculation, easiness for discontinuous potential.
	==References==		==References==
	~~#[http:~~//dx.doi.org/10.1063/1.2038827 Guy J. Gloor, George Jackson, Felipe J. Blas and Enrique de Miguel "Test-area simulation method for the direct determination of the interfacial tension of systems with continuous or discontinuous potentials", Journal of Chemical Physics '''123''' 134703 (2005)]		<references/>
	[[category: computer simulation techniques]]		[[category: computer simulation techniques]]

Nice and Tidy: Added category

2008-02-07T10:47:51Z

Added category

← Older revision		Revision as of 12:47, 7 February 2008
Line 1:		Line 1:
	~~Related~~ to the [[test volume method]] for the pressure (which, in turn, is related to [[Widom test-particle method]]). The [[surface tension]] of a planar [[interface]] is given by the change in [[internal energy]] <math>\Delta U</math> caused by "squeezing" the system: modifying both the length in the direction normal to the interface and the area in the plane of the interface, in such a way that the total volume is left unchanged.		The '''test area method''' is related to the [[test volume method]] for the calculation of the [[pressure]] (which, in turn, is related to [[Widom test-particle method]]). The [[surface tension]] of a planar [[interface]] is given by the change in [[internal energy]] <math>\Delta U</math> caused by "squeezing" the system: modifying both the length in the direction normal to the interface and the area in the plane of the interface, in such a way that the total volume is left unchanged.

	It can be shown that the surface tension, if the changes are small, is given by:		It can be shown that the surface tension, if the changes are small, is given by:
Line 8:		Line 8:
	==References==		==References==
	#[http://dx.doi.org/10.1063/1.2038827 Guy J. Gloor, George Jackson, Felipe J. Blas and Enrique de Miguel "Test-area simulation method for the direct determination of the interfacial tension of systems with continuous or discontinuous potentials", Journal of Chemical Physics '''123''' 134703 (2005)]		#[http://dx.doi.org/10.1063/1.2038827 Guy J. Gloor, George Jackson, Felipe J. Blas and Enrique de Miguel "Test-area simulation method for the direct determination of the interfacial tension of systems with continuous or discontinuous potentials", Journal of Chemical Physics '''123''' 134703 (2005)]
			[[category: computer simulation techniques]]

Dduque: New page: Related to the test volume method for the pressure (which, in turn, is related to Widom test-particle method). The surface tension of a planar interface is given by the cha...

2008-02-07T10:05:44Z

New page: Related to the test volume method for the pressure (which, in turn, is related to Widom test-particle method). The surface tension of a planar interface is given by the cha...

New page

Related to the [[test volume method]] for the pressure (which, in turn, is related to [[Widom test-particle method]]). The [[surface tension]] of a planar [[interface]] is given by the change in [[internal energy]] <math>\Delta U</math> caused by "squeezing" the system: modifying both the length in the direction normal to the interface and the area in the plane of the interface, in such a way that the total volume is left unchanged.

It can be shown that the surface tension, if the changes are small, is given by:
:<math> \gamma = - \frac{ k_B T \Delta A } \log\langle \exp(-\Delta U/k_B T)\rangle. </math>

The expression parallels the one for the pressure in the [[test volume method]]; the advantages of this technique are also similar: avoidance of force calculation, easiness for discontinuous potential...

==References==
#[http://dx.doi.org/10.1063/1.2038827 Guy J. Gloor, George Jackson, Felipe J. Blas and Enrique de Miguel "Test-area simulation method for the direct determination of the interfacial tension of systems with continuous or discontinuous potentials", Journal of Chemical Physics '''123''' 134703 (2005)]