Application of Wertheim's thermodynamic perturbation theory to dipolar hard sphere chains

We present results from molecular simulation and statistical mechanics: bas ed theory for dipolar hard sphere chains. We consider tangent hard sphere c hains with dipoles on alternate segments. The equation of state is obtained by applying Wertheim's associating fluid theory in the total bonding limit to a mixture of non-polar and dipolar hard spheres. The equation of state of the chain requires the compressibility factor and pair correlation funct ions of this mixture which is the reference fluid. Computer simulation show s that the distribution function between the non-polar and polar hard spher es perpendicular to the dipole can be closely approximated by the hard sphe re distribution function. This result is consistent with results from the m ean spherical approximation and from reference linear hypernetted chain the ory. With this approximation we propose an equation of state for dipolar ha rd sphere chains.