Following publication of the previous article (DOI: 10.1002/jrs.3036) in the 2012 January issue of Journal of Raman Spectroscopy (Volume 43, Issue 1, pages 168–172), the assignment of some of the atomic displacements to the different Raman active vibrational modes in Figure 1 were incorrect.
The figure shown below shows the correct assignments. We also include a short table of the contributions of displacements of the different atomic positions to the Raman active modes. It is important to note that all the Raman active vibrational modes of 312 MAX phases involve the displacement of atoms located at the X position (i.e., Wyckoff position 4f; occupied by carbon and/or nitrogen), whereas none of the 211 Raman modes involve the displacement of any X atoms (i.e., Wyckoff position 2a). Likewise, none of the Raman active modes in 312 structures involve the displacement of MII atoms (i.e., Wyckoff position 2a). We thank Ms. Nina Lane (Drexel University) for her help and insightful discussions.