Pseudorotation

isotopic substitution."^[1]

conformers (envelope, twist).^[2] Note, no angular momentum is generated by this motion.^{[citation needed]} In these and related examples, a small displacement of the atomic positions leads to a loss of symmetry until the symmetric product re-forms (see image example below), where these displacements are typically along low-energy pathways.^{[citation needed]} The Berry mechanism refers to the facile interconversion of axial and equatorial ligand in MX₅ types of compounds, e.g. D_3h-symmetric PF₅ (shown).^[1][3] Finally, in a formal sense, the term pseudorotation is intended to refer exclusively to dynamics in symmetrical molecules, though mechanisms of the same type are invoked for lower symmetry molecules as well.^{[citation needed}