The EPR data for strained ruby have been reanalyzed using a model in which the mixing of five excited multiplets into the ground state are considered. Consistent crystal-field superposition-model parameters were obtained. Tables of the necessary superposition-model projection coefficients for both trigonally and tetragonally oriented coordinate systems are provided, making the application of the model to similar systems straightforward. Using this model, the justification for the Mller and Berlinger form of the superposition model for the Cr³⁺ ground state is investigated. Copyright © 1986 American Physical Society.