Revisit of rotational motion of axial poly-atomics by molecular dynamics simulation and group theory: liquid benzene at 298, 365, 432, 498, 562 K

Abstract

The paper reports quantitative physical aspects of the overall rotational motion of axially symmetric poly-atomics on the example of liquid benzene at five temperatures between 298 and 562 K on the basis of the group-theoretical approach proposed by B. Keller and F. Kneubűhl in Helv. Phys. Acta 45,1127 (1972), with a database generated by molecular dynamics simulation of ensemble-averaged orientational fluctuations. It is shown that (i) benzene rotates by a Markov process around an average, in-frame moving rotation axis and (ii) that numerous reported orientational correlation results that claim to display the rotational motion of the molecule, are nevertheless now to be considered irrelevant to their promulgated aim because their analyses omitted to account for the simultaneous inclination motion, as well as its particular time scale, of the average direction of the singular average molecular rotation axis of a benzene molecule.

Keywords:

• liquid benzene
• overall rotational motion
• rotational Markov process
• motion of average rotation axis