  Computation of entropy in liquids and liquid crystal phases is a big
challenge in statistical physics. In this work, we extend the two-phase
thermodynamic model (2PT) to shape anisotropic soft repulsive spherocylinders
(SRSs) and report the absolute values of entropy for different liquid crystal
(LC) phases for a range of aspect ratios L/D = 2-5. We calculate the density of
states (DoS) for different LC phases and decompose it into contributions
arising from translational and rotational degrees of freedom. The translational
and rotational modes are further partitioned into diffusive, gas-like, and
non-diffusive, solid-like components using a fluidicity factor. In the dilute
limit, the entropy values obtained from the 2PT method match exactly those of
an ideal rigid rotor. We find that, for a given packing fraction, the magnitude
of the total entropy is roughly equal regardless of the different LC phases
associated with different aspect ratios. We also compute the excess entropy
(for L/D = 5) and compare those with the values obtained using the standard
integration approach of molecular dynamics (MD) or Monte Carlo (MC) equation of
state (EOS) of SRS. The values obtained using both approaches match very well.
The rotational and translational fluidicity factors are further used to
determine the phase boundaries of different liquid crystal phases for the
respective aspect ratios.
