We have recently demonstrated a ¿hard-soft¿ route to new transition metal oxides, through the reduction at low temperatures of metastable phases obtained via high pressure. Two new SrCrO3-x phases with complex vacancy-ordered superstructures were prepared by reduction of the cubic high pressure perovskite SrCrO3. SrCrO2.8 has a long-period (66 Å) magnetic superstructure. To extend this ¿hard-soft¿ chemistry we are exploring BaCrO3 and CaCrO3, both of which require high pressure synthesis. BaCrO3 was reported in the 1980¿s but has not subsequently been characterized. Reduction under H2 at 400 °C of the high pressure cubic-type perovskite CaCrO3 gives a new phase of composition close to Ca2Cr2O5. We request beamtime here to study the crystal and magnetic structures of the 6H-BaCrO3 precursor, and of the new reduced brownmillerite-type Ca2Cr2O5.