We present the site-charge distribution in the charge-ordered and metallic states of ␣-͑BEDT-TTF͒ 2 I 3 , based on the assignment of the C v C stretching modes 2 , 3 , and 27 of ␣-͑BEDT-TTF͒ 2 I 3 with the aid of 13 C-and deuterium-substituted compounds. The nonuniform site charges in both the metallic and insulating phases were consistent with those determined by a recent x-ray diffraction study. Comparing the line shapes of the chargesensitive vibrational modes of ␣-͑BEDT-TTF͒ 2 I 3 with those of isostructural ␣-͑BEDT-TTF͒ 2 NH 4 Hg͑SCN͒ 4 , we propose a thermally activated fluctuation of charge order in the metallic phase of ␣-͑BEDT-TTF͒ 2 I 3. This fluctuation was considerably suppressed above 0.65 GPa. The optical conductivity in the metallic phase shows no Drude response.

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This is one of a series of studies on the reversal of the helix sense of polyaspartates originated from the pioneering work of Goodman and his associates in 1960s. Poly(␤-p-chlorobenzyl L-aspartate) (PClBLA)

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Direct structural characterization of charge localization in metal to ligand charge transfer complexes AIP Conf.Pressure dependence of optical absorption spectra were measured for ͑phthalocyaninato͒-nickel hexafluoroarsenate, NiPc(AsF 6 ) 0.5 and ͑phthalocyaninato͒-cobalt hexafluororarsenate, CoPc(AsF 6 ) 0.5 . We found a charge transfer from the central metal ion to the macrocycle at 0.5 GPa in NiPc(AsF 6 ) 0.5 and 1.1 GPa in CoPc(AsF 6 ) 0.5 . According to the electron-filling process in the -conduction band, a metal-insulator transition and an evolution of the energy gap was observed in NiPc(AsF 6 ) 0.5 . On the other hand, nonmetallic CoPc(AsF 6 ) 0.5 showed a continuous change.