Atomistic Simulations of a Thermotropic Biaxial Liquid Crystal

We have performed molecular dynamics simulations of a 2,5-bis-(p-hydroxyphenyl)-1,3,4-oxadiazole\udmesogen ODBP-Ph-C7 at a fully atomistic level for a range of temperatures within the region that has\udexperimentally been assigned to a biaxial nematic phase. Analysis of the data shows that the simulated\udnematic phase is biaxial but that the degree of biaxiality is small. The simulations show also the formation\udof ferroelectric domains in the nematic where the molecular short axis is aligned with the oxadiazole\uddipoles parallel to each other. Removal of electrostatic interactions leads to destabilization of ferroelectric\uddomains and destabilization of the biaxiality. An additional simulation shows the slow growth of a\udmesophase directly from the isotropic fluid over a period of approximately 50 ns. This is the first time this\udhas been achieved within the framework of an all-atom model