Understanding the THz spectrum of L-cysteine

In this article we look at understanding the THz spectra of L-cysteine. L-cysteine exhibits a high degree of polymorphism with Form I being the most stable. This polymorph however shows disorder above 30 K via rotation around the C-C-S-H torsion angle. We aim to understand how this disorder influences the THz spectrum using a combination of static DFT phonon calculation of a number of different supercells along with molecular dynamics simulations of appropriate structures.