  By Wertheim method the exact solution of the Percus-Yevick integral equation
for a system of particles with the "repulsive step potential",interacting
("collapsing" hard spheres) is obtained. On the basis of this solution the
state equation for the "repulsive step potential" is built and determined, that
the Percus-Yevick equation does not show the Van der Waalse loop for
"collapsing" hard spheres.
