VIRIAL-COEFFICIENTS OF ONSAGER CROSSES

Onsager crosses are particles formed by rigidly connecting three perpe ndicular, elongated rods of length L and diameter D. We have investiga ted the behaviour of the virial coefficients of Onsager crosses as a f unction of the aspect ratio LID of the rods. The interest in these par ticles stems from the fact that they should exhibit a cubatic liquid c rystalline phase in the limit (L/D) --> infinity. It is shown that in order for the theory predicting this phase to be strictly valid, the r od aspect ratio should be extremely large ((L/D) greater than or simil ar to 1000).