Hard spherocylinders

The hard spherocylinder model consists on an impenetrable cylinder, capped at both ends by hemispheres whose diameters are the same as the diameter of the cylinder. The molecular volume of the spherocylinder is given by

$v_{0}=\pi \left({\frac {LD^{2}}{4}}+{\frac {D^{3}}{6}}\right)$

where $L$ is the length of the cylindrical part of the spherocylinder and $D$ is the diameter.

Minimum distance

The minimum distance between two spherocylinders can be calculated using an algorithm published by Vega and Lago (Ref. 1). The source code can be found here. Such an algorithm is essential in, for example, a Monte Carlo simulation, in order to check for overlaps between two sites.

1. Carlos Vega and Santiago Lago "A fast algorithm to evaluate the shortest distance between rods", Computers & Chemistry 18 pp. 55-59 (1994)

See also

• Charged hard spherocylinders

References

1. S. C. McGrother and D. C. Williamson and G. Jackson "A re-examination of the phase diagram of hard spherocylinders", Journal of Chemical Physics 104 pp. 6755-6771 (1996)
2. P. Bolhuis and D. Frenkel "Tracing the phase boundaries of hard spherocylinders", Journal of Chemical Physics 106 pp. 666-687 (1997)
3. Giorgio Cinacchi and Yuri Martínez-Ratón and Luis Mederos and Enrique Velasco "Smectic, nematic, and isotropic phases in binary mixtures of thin and thick hard spherocylinders", Journal of Chemical Physics 124 pp. 234904 (2006)