Gay-Berne model

The Gay-Berne model is used extensively in simulations of liquid crystalline systems. The Gay-Berne model is an anisotropic form of the Lennard-Jones 12:6 potential. \[U_{ij}^{\mathrm LJ/GB} = 4 \epsilon_0^{\mathrm LJ/GB} [\epsilon^{\mathrm LJ/GB}]^{\mu} ( {\mathbf {\hat u}}_j , {\mathbf {\hat r}}_{ij} ) \times \left[ \left( \frac{\sigma_0^{\mathrm LJ/GB} } { r_{ij} - \sigma^{\mathrm LJ/GB} ({\mathbf {\hat{u}}}_j, {\mathbf {\hat{r}}}_{ij} ) + {\sigma_0}^{\mathrm LJ/GB} } \right)^{12} - \left( \frac { \sigma_0^{\mathrm LJ/GB} } { r_{ij} - \sigma^{\mathrm LJ/GB} ({\mathbf {\hat{u}}}_j, {\mathbf {\hat{r}}}_{ij} ) + {\sigma_0}^{\mathrm LJ/GB} } \right)^{6} \right], \]

where, in the limit of one of the particles being spherical, gives:

\[\sigma^{\mathrm LJ/GB} ({\mathbf {\hat{u}}}_j, {\mathbf {\hat{r}}}_{ij} ) ={\sigma_0}{[1 - \chi \alpha^{-2} {({\mathbf {\hat{r}}}_{ij} \cdot {\mathbf {\hat{u}}}_j )}^{2}]}^{-1/2}\]

and

\[\epsilon^{\mathrm LJ/GB}({\mathbf {\hat{u}}}_j, {\mathbf {\hat{r}}}_{ij} ) ={\epsilon_0}{[1 - \chi\prime \alpha\prime^{-2} {({\mathbf {\hat{r}}}_{ij} \cdot {\mathbf {\hat{u}}}_j )}^{2}]}\]

with

\[\frac{\chi}{\alpha^{2}}=\frac{l_{j}^{2}-d_{j}^{2}}{l_{j}^{2}+d_{i}^{2}}\]

and

\[\frac{\chi \prime }{\alpha \prime^{2}}=1- {\left(\frac{\epsilon_{ee}}{\epsilon_{ss}}\right)} ^{\frac{1}{\mu}}.\]

Phase diagram

Main article: Phase diagram of the Gay-Berne model

References

Related reading

• R. Berardi, C. Fava and C. Zannoni "A generalized Gay-Berne intermolecular potential for biaxial particles", Chemical Physics Letters 236 pp. 462-468 (1995)
• Douglas J. Cleaver, Christopher M. Care, Michael P. Allen, and Maureen P. Neal "Extension and generalization of the Gay-Berne potential" Physical Review E 54 pp. 559-567 (1996)
• Roberto Berardi, Carlo Fava, Claudio Zannoni "A Gay–Berne potential for dissimilar biaxial particles", Chemical Physics Letters 297 pp. 8-14 (1998)