Temporal and structural characteristics of a two dimensional gas of hard needles

We have simulated the dynamics of a two dimensional gas of hard
needles by event-oriented molecular dynamics in NEV ensemble. Various
quantities namely longitudinal and transverse velocity
auto-correlation functions, translational and rotational diffusion
constants, static structure factors and radial distribution function
have been obtained and their dependence on density are
characterised. Although the positional order parameter shows ideal gas
behaviour, the orientational degree of freedom behaves nontrivially
and exhibits interesting features. Slowing down is observed in the
angular part of the motion. The dependence of translational diffusion
coefficient on the density is analogous to the 3D gas of hard
needles. It is shown that above a density the rotational mean squared
displacement exhibits a three stage regime which can be attributed to
glassy-like behaviour.