Vibrational spectra of guanylurea(1+) hydrogen phosphite-Novel remarkable material for nonlinear optics

The vibrational spectra of a novel material exhibiting remarkable linear and nonlinear optical properties, guanylurea(1+) hydrogen phosphite, have been studied. The FTIR and FT Raman spectra of its polycrystalline samples at the room temperature have been recorded along with polarized Raman spectra of its oriented single crystal slice. The assignment of vibrational bands is based on quantum-chemical computations of the guanylurea cation performed at the B3LYP level with 6-311 + G(d,p) basis set and the results of nuclear site group analysis.