The fallacy of edge elements

The present paper critically investigates the use of edge elements for computing electromagnetic fields. The application of edge elements in methods based on the use of vector potentials as well as in methods that compute electric and/or magnetic fields directly will be covered. In particular the popular idea that edge elements eliminate spurious solutions will be refuted. This erroneous idea is replaced by the insight that spurious solutions can be eliminated only by a proper finite-element formulation. A reference is made to alternative approaches, one of them introducing a new type of element, the so-called generalised Cartesian element, that combines the advantages of the classical Cartesians (nodal) elements with the ability of edge elements to allow the representation of discontinuities.