pseudorotation
/ˌs(j)uːdə(ʊ)rə(ʊ)ˈteɪʃn/Chemistry
noun
A change in molecular configuration involving concerted displacements of the constituent atoms, which is equivalent to a rotation of the molecule (in some cases coupled with an interchange of some of the constituents), but does not involve any actual rotation of the molecule.
Origin
1940s. From pseudo- + rotation. Compare later pseudorotate.