Static and dynamic molecular properties of real and simulated PCH5

Abstract

We present the results of a realistic computer simulation of a liquid crystal: trans-4-n-pentyl-1-(4-cyanophenyl)cyclohexane (PCH5) and perform detailed comparisons between the molecular properties of the real and the simulated substance. With the aim of obtaining additional knowledge on its dynamic properties, the spontaneous Raman spectrum of PCH5 has been studied and the shape of the 2226 cm⁻¹ band has been analysed. The data on static parameters have been taken from literature. Simulation data were obtained by a molecular dynamics method with 50 flexible molecules interacting through a site–site potential in a box with periodic boundary conditions. Analysis of static parameters >D ^L _0m< and the time correlation functions >D _{L m0}<(0)D ^L _m0(t)< (where D are Wigner functions) in the isotropic and the nematic phases on the one hand provide evidence for the advantages of the interpretation of experimental results on the basis of simulation data, and on the other hand such a comparative study helps understanding of the nature of some problems existing with regard to computer simulations of the mesophase with a realistic molecular interaction potential.