Photoinduced Absorption Spectra of Halogen-Bridged Binuclear Metal   Complexes: Possible Contrast between R_4_[Pt_2_(P_2_O_5_H_2_)_4_X]nH_2_O and   Pt_2_(CH_3_CS_2_)_4_I
  The optical conductivity of photogenerated solitons in quasi-one-dimensional halogen-bridged binuclear metal (MMX) complexes is investigated with particular emphasis on a comparison between the two family compounds R_4_[Pt_2_(P_2_O_5_H_2_)_4_X]nH_2_O (X=Cl,Br,I;R=NH_4_,Na,K,...; pop=diphosphonate=P_2_O_5_H_2_^2-^) and Pt_2_(dta)_4_I (dta=dithioacetate=CH_3_CS_2_^-^). Soliton-induced absorption spectra for the pop complexes should split into two bands, while those for the dta complex should consist of a single band. 
Jun Ohara and Shoji Yamamoto