Terahertz absorption spectra and potential energy distribution of liquid crystals

•THz absorption spectra of liquid crystals 5CB, 5OCB, and PCH5 were investigated.•The absorption frequencies were calculated theoretically using Gaussian 09 software.•The vibrational modes were assigned accurately by PED analysis.•The impacts of core structures on the THz absorption spectra were discussed.

In this work, the terahertz (THz) absorption spectra of a set of nematic liquid crystals were studied using the density functional theories (DFT). An accurate assignment of the vibrational modes corresponding to absorption frequencies were performed using potential energy distribution (PED) in a frequency range of 0–3 THz. The impacts of different core structures on THz absorption spectra were discussed. The results indicate that scope of application must be considered in the LC-based THz device designing. This proposed work may give a useful suggestion on the design of novel liquid crystal material in THz wave.

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