  We consider depletion effects of a pear-shaped colloidal particle in a
hard-sphere solvent, for two different model realisations of the pear-shaped
colloidal particle. The two models are the pear hard Gaussian overlap (PHGO)
particles and the hard pears of revolution (HPR). The motivation for this study
is to provide a microscopic understanding for the substantially different
mesoscopic self-assembly properties of these pear-shaped colloids, in dense
suspensions, that have been reported in the first part of this series. This is
done by determining the differing depletion attraction via MC simulations of
PHGO and HPR particles in a pool of a hard spherical solvent and comparing them
with excluded volume calculations of numerically obtained ideal configurations
on the microscopic level. While the HPR model behaves as predicted by the
analysis of excluded volumes, the PHGO model showcases a preference for splay
between neighbouring particles, which can be attributed to the special
non-additive characteristics of the PHGO contact function. Lastly, we propose a
potentially experimentally realisable pear-shaped particle model, the
non-additive hard pear of revolution (NAHPR) model, which is based on the HPR
model but also features non-additive traits similar to those of PHGO particles
to mimic their depletion behaviour.
