A Born-Green-Yvon (BGY) integral equation approach is used to study th
e structure and thermodynamics of a fluid of fused hard sphere dimers.
Starting from a BGY equation for the dimer molecular pair distributio
n function, an equation for the simpler site-site distribution is deri
ved. The multisite distribution functions appearing in this latter equ
ation are related to the site-site function via a set of superposition
approximations. Detailed results are presented for dimers with bond l
engths of L = 0.6sigma and 1.0sigma (where sigma is the hard sphere si
te diameter). These results, which include the site-site distribution
function over a range of densities, as well as the virial and compress
ibility pressure equations of state, are compared with analytic and Mo
nte Carlo results.