Green BaIn0.80Mn0.20O2.70 (51) has been synthesized by solid-state reaction under high temperature, and black BaIn0.80Mn0.20O2.60 (RS1) is obtained by treating S1 under vacuum at 500 degrees C. They were characterized by powder X-ray and neutron diffraction, selected area electron diffraction, magnetic measurement, and impedance spectrum. S1 and RS1 crystallize in Cmcm (a = 5.9722(3), b = 5.9664(3), c = 8.4511(4) angstrom) and P2(1)/c (a = 5.9328(7), b = 5.9445(11), c = 16.8154(14) angstrom, beta = 90.02(2)degrees), respectively. Oxide ion vacancies are confirmed to exist in S1 and RS1 by the neutron diffraction data. (C)2014 Elsevier B.V. All rights reserved.