Since 2002, the structural science via Maximum Entropy Method based on synchrotron radiation(SR) diffraction data has driven an innovation of structural chemistry in Coordination Chemistry at SPring-8. The first successful contribution of the MEM Structural Science was a discovery of the peculiar structure of absorbed gas molecules in the nanopore of coordination polymer. The revealed one-dimensional array structure of absorbed gas molecules with no charge transfer made chemists recognize the power of Synchrotron Radiation as a probe of electrons in materials. The development of the MEM/Rietveld Method is described in terms of absorbed molecular site prediction as well as finding charge transfer among host-guest molecules. The expected role of the Next Generation Synchrotron Radiation facility under construction at Tohoku University Campus is also noted.
