Citation: Toriumi, K.; Yamashita, M.; Kurita, S.; Murase, I.; Ito, T. (1993). Phase transitions of the halogen-bridged M^II^--X--M^IV^ mixed-valence complexes [M(en)~2~][MX~2~(en)~2~](ClO~4~)~4~ (M = Pt,Pd; X = Cl, Br). Structural studies of the high- and low-temperature phases of [Pt(en)~2~][PtBr~2~(en)~2~](ClO~4~)~4~. Acta Crystallographica Section B, 49, pp. 497-506.