Analytical method for studying terahertz vibrations in a stearic acid single crystal

•We measured polarized terahertz absorption spectra of a stearic acid single crystal.•Several peaks were observed and angular dependences of intensity were analyzed.•Directions of THz vibrations were estimated. The anisotropy of terahertz absorption was investigated for a B-form single crystal of stearic acid. A polarized terahertz spectrometer was used to obtain absorption spectra over the range of 1–5THz. Seven vibrational modes were observed; four exhibited significant angular dependence. Additionally, we demonstrated a simple approach for estimating the angle of the dipole moment for each vibrational mode.