INTEGRAL-EQUATION AND COMPUTER-SIMULATION STUDIES OF HARD-SPHERES IN A SLIT PORE

The structure of a hard sphere fluid inside a planar slit pore is stud ied using integral equation and computer simulation approaches. A robu st and efficient method of numerically solving the one-particle Ornste in-Zernike (OZ) equation for the density profile in conjunction with a n arbitrary closure is described, which is an approximate Newton-Raphs on iteration in Fourier space. A new form of reference hypernetted cha in theory is proposed that uses the bridge function of a fluid of hard spheres near a hard wall as a reference system. This is tested agains t new grand canonical ensemble Monte Carlo computer simulation data ob tained herein and the results of other OZ equation based theories, inc luding the Percus-Yevick hypernetted chain, Martynov-Sarkisov and modi fied Verlet theory, at reduced bulk fluid number densities up to 0-7 a nd for pore sizes varying from 1.25 to 4.0. The proposed theory gives accurate density profiles and pressures for the entire range of slit s izes, and is superior to the other theories considered.