  Using atomistic molecular dynamics simulation we study the discotic columnar
liquid crystalline (LC) phases formed by a new organic compound having
Hexa-peri-Hexabenzocoronene (HBC) core with six pendant oligothiophene units
recently synthesized by Nan Hu et al. (N. Hu, R. Shao, Y. Shen, D. Chen, N. A.
Clark and D. M. Walba, Adv. Mater. 26, 2066, 2014). This HBC core based LC
phase was shown to have electric field responsive behavior and has important
application in organic electronics. Our simulation results confirm the
hexagonal arrangement of columnar LC phase with a lattice spacing consistent
with that obtained from small angle X-ray diffraction data. We have also
calculated various positional and orientational correlation functions to
characterize the ordering of the molecules in the columnar arrangement. The
molecules in a column are arranged with an average twist of 25 degrees having
an average inter-molecular separation of ~5 {\AA}. Interestingly, we find an
overall tilt angle of 43 degrees between the columnar axis and HBC core. We
also simulate the charge transport through this columnar phase and report the
numerical value of charge carrier mobility for this liquid crystal phase. The
charge carrier mobility is strongly influenced by the twist angle and average
spacing of the molecules in the column.
