  Low as well as high-temperature electron and x-ray diffraction studies have
been carried out on a rare-earth free B-site disordered electron-doped
manganite SrMn0.875.Mo0.125O3-{\delta} in the temperature range of 83K to 637K.
These studies reveal the occurrence of strong charge ordering (CO) at room
temperature in a pseudo tetragonally distorted perovskite phase with
space-group Pmmm. Non integral modulation vector of 8.95 times along [-110]
indicates a charge density wave type modulation. The CO phase with basic
perovskite structure Pmmm transforms to a charge disorder cubic phase through a
first order phase transition at 355K. Supporting temperature dependent
measurements of resistance and magnetization show a metal-insulator and
antiferromagnetic transitions across 355K with a wide hysterisis ranging from
150K to 365K. The occurrence of pseudo tetragonality of the basic perovskite
lattice with c/a < 1 together with charge-ordered regions with 2-dimensional
modulation have been analyzed as the coexistence of two CO phases with
3dx2/3dy2 type and 3dx2-y2 type orbital ordering.
