If muon-to-electron conversion in the field of a nucleus is found in the current generation
of experiments (i.e. Mu2e or COMET), the measurement of the atomic number dependence of the process will become
an important experimental goal. We present a new treatment of the (Z,A) dependence of muon to-
electron conversion. Our approach differs from earlier work in that it combines nuclear charge
distribution determinations from both electron scattering and muonic atoms, takes into account
the effect of permanent quadrupole deformations, and employs a Hartree-Bogliubov model for the
neutron distributions. The results are compared with earlier calculations.