An einstein relativistic atomic and molecular model based on the Horwitz–Piron–Reuse theory

The Einsteinian quantum mechanics proposed by Horwitz, Piron, and Reuse is formulated in a way appropriate for atomic and molecular calculations. In this theory each particle is described by a four‐coordinate x μ = ( ct , x ), and the existence of a common Lorenz invariant time ordering parameter τ is postulated. For spin‐½ particles there exists in addition a superselection rule n defined by the Stern–Gerlach experiment. The description of an atom/molecule in the external approximation is given. We then formulate a method (the self‐consistent energy method) by which conventional calculation procedures can be applied within the theory. The calculation of the expectation value of a singular term which is the analog of the conventional Darwin term, is demonstrated by calculating the energy of an electron in a Coulomb field to the order α 4 . This calculation also demonstrates the validity of the Pauli approximation within the theory.