Methane Symmetry Operations - Figure 3

Figure 3. (a) An arbitrary instantaneous configuration of the methane molecule; (b) rotation of vibrational displacement vectors through an angle −2π/3 about the (111) direction, as required for the point group operation C₃ (111); (c) transformation of rotational angles corresponding to a rotation of the frame through an angle of +2π/3 about the (111) direction, as required for C₃ (111). Figure (3c) can be generated from Fig. (3a) by the permutation (132) as defined in Section 3.