1202.0505 (Gerardo Odriozola)

Revisiting the phase diagram of hard ellipsoids    [PDF]

Gerardo Odriozola

In this work the well-known Frenkel-Mulder phase diagram of hard ellipsoids
of revolution [Mol. Phys. 55, 1171 (1985)] is revisited by means of replica
exchange Monte Carlo simulations. The method provides good sampling of dense
systems and so, solid phases can be accessed without the need of imposing a
given structure. At high densities, we found plastic and ordered FCC crystals
for semi-spherical ellipsoids (prolates and oblates), and SM2 crystal
structures [Phys. Rev. E 75, 020402 (2007)] for x:1-prolates and 1:x-oblates
with x >= 3. The revised fluid-crystal and isotropic-nematic transitions
reasonably agree with those presented in the Frenkel-Mulder diagram. An
interesting result is that, for small system sizes (100 particles), we obtained
2:1 and 1.5:1-prolate equations of state without transitions, while the systems
developed some order at large densities. Furthermore, the symmetric oblate
cases are also reluctant to form ordered phases.

View original: http://arxiv.org/abs/1202.0505