Low frequency modes of biomolecules in the hydrated states

Hydration process of few organic molecules is examined in the low-frequency region under 100 cm^-1. THz spectra of both hydrated states and anhydrous states in the solid crystal samples are measured by the THz-TDS instrument and their vibrational modes are analyzed by periodic boundary condition implemented DFT calculation. By comparing with single molecule calculation, peak assignment of their peaks was performed and the effects of each water molecules which bind to the anhydrous molecules are discussed.