Proton Tunneling Detected in Cesium Silicate Compound LDS-l

In low dimensional cesium silicate compound LDS-1 with extremely short hydrogen-bonding distance, proton tunneling was successfully detected in the wide-range of absorbance spectra (10-7800 cm^-1). The optical transitions and energy level schemes were demonstrated through the analysis of eigenvalue problem for symmetric double-minimum potentials. Moreover we identified two different collective modes of protonic vibrations.