Buckingham potential: Difference between revisions

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The '''Buckingham potential''' is given by
The '''Buckingham potential''' is given by <ref>[http://dx.doi.org/10.1098/rspa.1938.0173 R. A. Buckingham "The Classical Equation of State of Gaseous Helium, Neon and Argon", Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences '''168''' pp. 264-283 (1938)]</ref>


:<math>\Phi_{12}(r) = A \exp \left(-Br\right) - \frac{C}{r^6}</math>
:<math>\Phi_{12}(r) = A \exp \left(-Br\right) - \frac{C}{r^6}</math>
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where <math>\Phi_{12}(r)</math> is the [[intermolecular pair potential]], <math>r := |\mathbf{r}_1 - \mathbf{r}_2|</math>, and <math>A</math>, <math>B</math> and <math>C</math> are constants.
where <math>\Phi_{12}(r)</math> is the [[intermolecular pair potential]], <math>r := |\mathbf{r}_1 - \mathbf{r}_2|</math>, and <math>A</math>, <math>B</math> and <math>C</math> are constants.


It is named for R. A. Buckingham, and not as is often thought for David Buckingham.
The Buckingham potential describes the exchange repulsion, which originates from the Pauli exclusion principle, by a more realistic exponential function of distance, in contrast to the inverse twelfth power used by the [[Lennard-Jones model |Lennard-Jones potential]]. However, since the Buckingham potential remains finite even at very small distances, it runs the risk of an un-physical "Buckingham catastrophe" at short range when used in simulations of charged systems.This occurs when the electrostatic attraction artificially  overcomes the repulsive barrier. The Lennard-Jones potential is also quicker to compute, and so is more frequently used in [[Computer simulation techniques | computer simulations]].
 
The Buckingham potential describes the repulsive exchange repulsion that originates from the Pauli exclusion principle by a more realistic exponential function of distance, in contrast to the inverse twelfth power used by the Lennard-Jones potential. However, since the Buckingham potential is finite even at very small distances, it runs the risk of an unphysical "Buckingham catastrophe" at short range when used in simulations of charged systems; this occurs when the electrostatic attraction artifactually overcomes the repulsive barrier. The Lennard-Jones potential is also quicker to compute, and is more frequently used in [[molecular dynamics]] and other simulations.


==References==
==References==
#[http://dx.doi.org/10.1098/rspa.1938.0173 R. A. Buckingham "The Classical Equation of State of Gaseous Helium, Neon and Argon", Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences '''168''' pp. 264-283 (1938)]
<references/>
[[category: models]]
[[category: models]]

Revision as of 18:59, 2 February 2010

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The Buckingham potential is given by [1]

where is the intermolecular pair potential, , and , and are constants.

The Buckingham potential describes the exchange repulsion, which originates from the Pauli exclusion principle, by a more realistic exponential function of distance, in contrast to the inverse twelfth power used by the Lennard-Jones potential. However, since the Buckingham potential remains finite even at very small distances, it runs the risk of an un-physical "Buckingham catastrophe" at short range when used in simulations of charged systems.This occurs when the electrostatic attraction artificially overcomes the repulsive barrier. The Lennard-Jones potential is also quicker to compute, and so is more frequently used in computer simulations.

References