  Line optical tweezer and colloidal-probe atomic force microscopy can measure
force curves between two large colloidal particles of chemically the same
surfaces in a suspension of small colloidal particles. Recently, the authors
proposed a transform theory to obtain the number density distribution of the
small colloidal particles on the large colloidal particle from the force curve.
In this short letter, we propose another method which utilizes Ornstein-Zernike
equation coupled with a closure equation instead of Kirkwood superposition
approximation. The new transform theory uses a structure factor measured by
x-ray or neutron scattering, and applies Nelder-Mead method to find the
solution. Since it is known that Ornstein-Zernike equation coupled with the
closure equation is accurate compared with Kirkwood superposition
approximation, the new transform theory is theoretically better than the
previous methods when the structure factor and the closure equation are
reliable.
