Measurement and DFT Calculation on Terahertz Spectroscopy of 4-aminobenzoic Acid

Rensselaer Polytechnic Institute Center for terahertz Research Troy NY 12180 USA
Journal of infrared, millimeter and terahertz waves (Impact Factor: 1.94). 03/2010; 31(3):310-318. DOI: 10.1007/s10762-009-9591-6


We report the measurement of the terahertz (THz) spectra of 4-aminobenzoic acid by using Fourier transform infrared (FTIR)
spectroscopy in the 1.5–19.5THz. Low frequency intermolecular (or phonon) modes between 0.3 and 2.4THz were also investigated
via THz time-domain spectroscopy. Structure and vibrational frequencies of the sample were calculated through density functional
theory(DFT). The calculated results are in agreement with the experimental data. Moreover, we have interpreted observed vibrational
frequencies using DFT. Two intermolecular or phonon modes were identified at 1.54 and 2.19THz.

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