# Buckingham potential

The **Buckingham potential** is given by ^{[1]}

\[\Phi_{12}(r) = A \exp \left(-Br\right) - \frac{C}{r^6}\]

where \(\Phi_{12}(r)\) is the intermolecular pair potential, \(r := |\mathbf{r}_1 - \mathbf{r}_2|\), and \(A\), \(B\) and \(C\) 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 about 4 times quicker to compute ^{[2]} and so is more frequently used in computer simulations.

## See also[edit]

## References[edit]

- ↑ 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) - ↑ David N. J. White "A computationally efficient alternative to the Buckingham potential for molecular mechanics calculations", Journal of Computer-Aided Molecular Design
**11**pp.517-521 (1997)

- Related reading