  We predict theoretically the existence of a class of colloidal structures in
nematic liquid crystal (NLC) cells, which are induced by surface patterns on
the plates of the cell (like cells with UV-irradiated polyimide surfaces using
micron size masks). These bulk structures arise from non-zero boundary
conditions for the director distortions at the confining surfaces. In
particular, we demonstrate that quadrupole spherical particles (like spheres
with boojums or Saturn-ring director configurations) form a square lattice
inside a planar NLC cell, which has checkerboard patterns on both its plates.
