Methane Symmetry Operations - Figure 4

Figure 4. (a) An arbitrary instantaneous configuration of the methane molecule; (b) rotation of vibrational displacement vectors through an angle −π/2 about the x axis, followed by their reflection in the yz plane, as required for the point group operation S₄(x); (c) transformation of rotational angles corresponding to a rotation of the frame through an angle +3π/2 about the x axis, as required for S₄(x) by (eq. 18). Figure (4c) can be generated from Fig. (4a) by the permutation (1432)* as defined in Section 3.