Molecular modeling of a polar rod-like aromatic polyester forming nematic liquid crystal. Part 2. Molecular dynamics simulation for polar associationof molecules

The most stable molecular packing systems of aromatic polyester molecules h ave been investigated by molecular dynamics (MD) simulations performed for decamer (ten repeating units) of p-hydroxybenzoic acid (HBA) in the nematic phase. The MD simulations were started from eight possible packing structu res. Among them, we found the polar ordering structure with the intermolecu lar ester carbonyl groups aligned in the same direction is energetically mo st favorable. This is consistent with our previous experimental observation for the second-harmonic generation (SHG) intensity measurement.