United-atom model - Revision history

Carl McBride: Added a recent publication

2017-05-23T10:21:00Z

Added a recent publication

← Older revision		Revision as of 12:21, 23 May 2017
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	{{Stub-general}}		{{Stub-general}}
	In the '''united-atom model''' the <math>CH_2</math> and <math>~~CH_3~~</math> units		In the '''united-atom model''' the <math>CH_2</math>, <math>CH_3</math> and <math>CH_4</math> units
	are treated as one unified interaction site (hence ''united-atom''), i.e. the hydrogen atoms are incorporated within		are treated as one unified interaction site (hence ''united-atom''), i.e. the hydrogen atoms are incorporated within
	the carbon atoms and are not expressed explicitly. Many [[force fields]]		the carbon atoms and are not expressed explicitly. Many [[force fields]]
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	14 hydrogen atoms. A fully-atomistic model of ''n''-hexane would		14 hydrogen atoms. A fully-atomistic model of ''n''-hexane would
	require 20 interaction sites. Using the united-atom approximation, this reduces to		require 20 interaction sites. Using the united-atom approximation, this reduces to
	two <math>CH_3</math> sites and four <math>CH_2</math> sites, a significant reduction.		two <math>CH_3</math> sites and four <math>CH_2</math> sites, a significant reduction. The interaction sites are usually parametrised [[Lennard-Jones model \| Lennard-Jones potentials]].
	==Justification==		==Justification==
	==Parameters==		==Parameters==
	==References==		==References==
	#[http://dx.doi.org/10.1080/00268978800101181 Rolf Lustig and William A. Steele "On the thermodynamics of liquid propane", Molecular Physics '''65''' pp. 475-486 (1988)]		<references/>
	#[http://dx.doi.org/10.1063/1.454894 Sumnesh Gupta, Jia-an Yang and Neil R. Kestner "Computer modeling of liquid propane using three-site potential models", Journal of Chemical Physics '''89''' pp. 3733-3741 (1988)]		;Related reading
	#[http://dx.doi.org/10.1063/1.456853 Søren Toxvaerd "Molecular dynamics calculation of the equation of state of liquid propane", Journal of Chemical Physics '''91''' pp. 3716-3720 (1989)]		*[http://dx.doi.org/10.1080/00268978800101181 Rolf Lustig and William A. Steele "On the thermodynamics of liquid propane", Molecular Physics '''65''' pp. 475-486 (1988)]
	#[http://dx.doi.org/10.1063/1.458709 Søren Toxvaerd "Molecular dynamics calculation of the equation of state of alkanes", Journal of Chemical Physics '''93''' pp. 4290-4295 (1990)]		*[http://dx.doi.org/10.1063/1.454894 Sumnesh Gupta, Jia-an Yang and Neil R. Kestner "Computer modeling of liquid propane using three-site potential models", Journal of Chemical Physics '''89''' pp. 3733-3741 (1988)]
			*[http://dx.doi.org/10.1063/1.456853 Søren Toxvaerd "Molecular dynamics calculation of the equation of state of liquid propane", Journal of Chemical Physics '''91''' pp. 3716-3720 (1989)]
			*[http://dx.doi.org/10.1063/1.458709 Søren Toxvaerd "Molecular dynamics calculation of the equation of state of alkanes", Journal of Chemical Physics '''93''' pp. 4290-4295 (1990)]
			*[http://dx.doi.org/10.1063/1.4983406 Richard A. Messerly, Thomas A. Knotts IV, and W. Vincent Wilding "Uncertainty quantification and propagation of errors of the Lennard-Jones 12-6 parameters for n-alkanes", Journal of Chemical Physics '''146''' 194110 (2017)]


	[[Category: Models]]		[[Category: Models]]

Carl McBride at 12:50, 17 October 2007

2007-10-17T12:50:12Z

← Older revision		Revision as of 14:50, 17 October 2007
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			{{Stub-general}}
	In the '''united-atom model''' the <math>CH_2</math> and <math>CH_3</math> units		In the '''united-atom model''' the <math>CH_2</math> and <math>CH_3</math> units
	are treated as one unified interaction site (hence ''united-atom''), i.e. the hydrogen atoms are incorporated within		are treated as one unified interaction site (hence ''united-atom''), i.e. the hydrogen atoms are incorporated within

Carl McBride: /* References */

2007-10-16T18:54:09Z

References

← Older revision		Revision as of 20:54, 16 October 2007
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	==Parameters==		==Parameters==
	==References==		==References==
			#[http://dx.doi.org/10.1080/00268978800101181 Rolf Lustig and William A. Steele "On the thermodynamics of liquid propane", Molecular Physics '''65''' pp. 475-486 (1988)]
			#[http://dx.doi.org/10.1063/1.454894 Sumnesh Gupta, Jia-an Yang and Neil R. Kestner "Computer modeling of liquid propane using three-site potential models", Journal of Chemical Physics '''89''' pp. 3733-3741 (1988)]
			#[http://dx.doi.org/10.1063/1.456853 Søren Toxvaerd "Molecular dynamics calculation of the equation of state of liquid propane", Journal of Chemical Physics '''91''' pp. 3716-3720 (1989)]
	#[http://dx.doi.org/10.1063/1.458709 Søren Toxvaerd "Molecular dynamics calculation of the equation of state of alkanes", Journal of Chemical Physics '''93''' pp. 4290-4295 (1990)]		#[http://dx.doi.org/10.1063/1.458709 Søren Toxvaerd "Molecular dynamics calculation of the equation of state of alkanes", Journal of Chemical Physics '''93''' pp. 4290-4295 (1990)]
	[[Category: Models]]		[[Category: Models]]

Carl McBride at 17:05, 16 October 2007

2007-10-16T17:05:55Z

← Older revision		Revision as of 19:05, 16 October 2007
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	==Parameters==		==Parameters==
	==References==		==References==
			#[http://dx.doi.org/10.1063/1.458709 Søren Toxvaerd "Molecular dynamics calculation of the equation of state of alkanes", Journal of Chemical Physics '''93''' pp. 4290-4295 (1990)]
	[[Category: Models]]		[[Category: Models]]

Carl McBride at 17:22, 21 August 2007

2007-08-21T17:22:36Z

← Older revision		Revision as of 19:22, 21 August 2007
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	In the '''united-atom model''' the <math>CH_2</math> and <math>CH_3</math> units		In the '''united-atom model''' the <math>CH_2</math> and <math>CH_3</math> units
	are treated as one ~~point~~, i.e. the hydrogen atoms are incorporated within		are treated as one unified interaction site (hence ''united-atom''), i.e. the hydrogen atoms are incorporated within
	the carbon atoms and are not expressed explicitly. Many [[force fields]]		the carbon atoms and are not expressed explicitly. Many [[force fields]]
	make use of this approximation in order to reduce the computational		make use of this approximation in order to reduce the computational

Carl McBride at 09:44, 30 May 2007

2007-05-30T09:44:22Z

← Older revision		Revision as of 11:44, 30 May 2007
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	the carbon atoms and are not expressed explicitly. Many [[force fields]]		the carbon atoms and are not expressed explicitly. Many [[force fields]]
	make use of this approximation in order to reduce the computational		make use of this approximation in order to reduce the computational
	overheads.		overheads. For example, ''n''-hexane consists of 6 carbon atoms and
			14 hydrogen atoms. A fully-atomistic model of ''n''-hexane would
			require 20 interaction sites. Using the united-atom approximation, this reduces to
			two <math>CH_3</math> sites and four <math>CH_2</math> sites, a significant reduction.
			==Justification==
			==Parameters==
	==References==		==References==
	[[Category: Models]]		[[Category: Models]]

Carl McBride at 11:09, 29 May 2007

2007-05-29T11:09:47Z

← Older revision		Revision as of 13:09, 29 May 2007
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	In the '''united-atom model''' the <math>CH_2</math> and <math>CH_3</math> units		In the '''united-atom model''' the <math>CH_2</math> and <math>CH_3</math> units
	are treated as one point, i.e. the hydrogen atoms are incorporated within		are treated as one point, i.e. the hydrogen atoms are incorporated within
	the carbon atoms and are not expressed explicitly.		the carbon atoms and are not expressed explicitly. Many [[force fields]]
			make use of this approximation in order to reduce the computational
			overheads.
	==References==		==References==
	[[Category: Models]]		[[Category: Models]]

Carl McBride at 11:07, 29 May 2007

2007-05-29T11:07:33Z

← Older revision		Revision as of 13:07, 29 May 2007
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			In the '''united-atom model''' the <math>CH_2</math> and <math>CH_3</math> units
			are treated as one point, i.e. the hydrogen atoms are incorporated within
			the carbon atoms and are not expressed explicitly.
	==References==		==References==
	[[Category: Models]]		[[Category: Models]]

Carl McBride at 17:15, 20 March 2007

2007-03-20T17:15:20Z

← Older revision		Revision as of 19:15, 20 March 2007
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	==References==		==References==
			[[Category: Models]]

Carl McBride: New page: ==References==

2007-03-20T17:12:00Z

New page: ==References==

New page

==References==