A version of the nonrelativistic Schrödinger equation taking special relativity theory into account. The Dirac equation is needed to discuss the quantum mechanics of electrons in heavy atoms and, more generally, to discuss fine-structure features of atomic spectra, such as spin-orbit coupling. The equation was put forward by Paul Dirac in 1928. It can be solved exactly in the case of the hydrogen atom but can only be solved using approximation techniques for more complicated atoms.
Subjects: Chemistry — Physics.