An explicit, analytical calculation of homogenized cell parameters has been developed for centrally symmetric cells or supercells. For every principal direction, a set of one-directional (noneigenvalue) calculations driven by neutrons injected from outside generate transmission/reflection matrices from which diffusion coefficient and cross-section matrices, generally full, are obtained analytically. The analytical calculation of the homogenized parameters is carried through for two different angular distributions of the injected neutrons (generic, P1) and for two mesh structures (ultrafine, 1 mesh/cell). Reaction-rate matching cross-section matrices are also obtained and are shown to be related to the conventional edge-flux normalized cross sections. Two test problems, covering both heavy water and light water lattices, show the superiority of the homogenized diffusion theory (HDT) parameters over the traditional ones: In the light water lattice problem, the HDT constants perform even better than analogous constants generated by other authors.