Abstract When a cluster of particles is immersed in a uniform
electric field,the particles are coupled together due to the mutual interaction among them.This
interaction causes the dipole moment of the cluster to be dependent upon the spatial
arrangement and relative permittivity of the particles and upon the cluster size.In this work,we
attempt to estimate the dipole moment of finite cubic arrays of particles,in terms of that of
particle chains which has been known.We assume that a chain may be replaced by a single
equivalent sphere with the same dipole moment.With replacing the chain by equivalent
sphere,a cluster is simplified to a planar array,and this planar array is simplified to a
chain,then the dipole moment is obtained.Numerical calculations are performed.It is found that
our results are acceptable.