RT Journal Article
T1 The global phase diagram of the Gay–Berne model
A1 Miguel Agustino, Enrique de
A1 Vega, C.
AB The phase diagram of the Gay–Berne model with anisotropy parameters k53, k 855 has beenevaluated by means of computer simulations. For a number of temperatures, NPT simulations wereperformed for the solid phase leading to the determination of the free energy of the solid at areference density. Using the equation of state and free energies of the isotropic and nematic phasesavailable in the existing literature the fluid–solid equilibrium was calculated for the temperaturesselected. Taking these fluid–solid equilibrium results as the starting points, the fluid–solidequilibrium curve was determined for a wide range of temperatures using Gibbs–Duhemintegration. At high temperatures the sequence of phases encountered on compression is isotropic tonematic, and then nematic to solid. For reduced temperatures below T50.85 the sequence is fromthe isotropic phase directly to the solid state. In view of this we locate the isotropic–nematic–solidtriple point at TINS50.85. The present results suggest that the high-density phase designated smecticB in previous simulations of the model is in fact a molecular solid and not a smectic liquid crystal.It seems that no thermodynamically stable smectic phase appears for the Gay–Berne model with thechoice of parameters used in this work. We locate the vapor–isotropic liquid–solid triple point at atemperature TVIS50.445. Considering that the critical temperatures is Tc50.473, the Gay–Bernemodel used in this work presents vapor–liquid separation over a rather narrow range oftemperatures. It is suggested that the strong lateral attractive interactions present in the Gay–Bernemodel stabilizes the layers found in the solid phase. The large stability of the solid phase,particularly at low temperatures, would explain the unexpectedly small liquid range observed in thevapor–liquid region.
PB American Institute of Physics
SN 0021-9606
SN 1089-7690 (electrónico)
YR 2002
FD 2002
LK http://hdl.handle.net/10272/9577
UL http://hdl.handle.net/10272/9577
LA eng
NO Miguel Agustino, E., Vega, C.: "The global phase diagram of the Gay–Berne model". Journal of Chemical Physics. Vo. 117, n. 13, págs. 6313-6322, (2002). ISSN  0021-9606
DS Repositorio Institucional de la Universidad de Huelva
RD 1 jun 2026