Here are slides used in class.
In addition to our lecture notes, please read this interactive online article on fluxional processes, as well as section IV of the original article by Berry.
Practice using these flashcards, and examine the SF4 BPR transition state vibrations.
Further resources: (i) the theoretical IR spectrum of PF5, (ii) animated normal modes for the IR-active vibrations of PF5, and (iii) supplemental exercises.
Note that the structure of PF5 has been studied by electron diffraction.