Assignment of Raman-active vibrational modes of tetragonal mackinawite: Raman investigations and ab initio calculations

We report on the first assignment of the Raman-active vibrational modes of mackinawite using Density Functional Perturbation Theory and direct methods with BLYP + dispersion correction. Based on experimental data and calculation results, the Raman bands were assigned as 236 cm −1 (B 1g ), 256 cm −1 (E g ), 376 cm −1 (A 1g ) and 395 cm −1 (E g ).