title: First principles investigation of L-alanine in terahertz region.
abstract: Terahertz absorption spectrum (0.5-4.0 THz) of L-alanine in the solid phase was measured by terahertz time-domain spectroscopy at room temperature. Simulations utilizing gaseous-state and solid-state theory were performed to determine the origins of the observed vibrational features. Our calculations showed that the measured features in solid-state materials could be well understood by considering the crystal packing interactions in a solid-state density functional theory calculation. Furthermore, intermolecular vibrations of L-alanine are found to be the dominating contributions to these measured spectral features in the range of 0.5-4.0 THz, except that located at 3.11 THz.
authors.affiliation: State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, 710119 China.
authors.forename: Zhuan-Ping
authors.initials: ZP
authors.lastname: Zheng
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Fan
keywords: L-alanine; Solid-state theory; THz-TDS