Highly oxidized transition metal cations in oxides tend to display unusual electronic and magnetic behavior due to the highly covalent nature of the M-O interactions. Iron is of particular interest, because the charge instabilities associated with unusually high oxidation states are often relieved through charge transitions such as charge disproportionation (CD) and intermetallic charge transfer (CT). We recently reported the high pressure synthesis of a new perovskite Ca0.5Bi0.5FeO3 which successively exhibits a CD transition at 250 K and a CT transition at 200 K. Both transitions are coupled to changes in the structural, magnetic, and transport properties. Sr doping suppresses the CT transition while Co participates in the CT with possible high/low spin state changes. We propose to collect neutron powder diffraction data from Ca0.5-xSrxBi0.5FeO3 and Ca0.5Bi0.5Fe1-xCoxO3.