Topics traditionally covered in an undergraduate course on quantum mechanics are included: Schrödinger’s wave equation and its application to one and three dimensions, potential wells, operator formalism and the theory of angular momentum, potential steps and barriers and tunnelling phenomena. Examples treated and modelled on the computer include the hydrogen atom, the diatomic molecule and the Kronig–Penney model of a one-dimensional solid. In addition this Computer Illustrated Text is able to include some subjects which are more advanced, such as the partial-wave treatment of scattering, and potential wells and barriers tilted by gravitational and electric fields. The principles behind these can be explained as the computer allows the solution of equations that are normally too complex for undergraduate texts.