The tracer correlation factor for diffusion via non-interacting vacancies was calculated by a Monte Carlo method for the simple-cubic lattice with a variable vacancy content. Particular emphasis was placed on obtaining results of very high precision. The results were in excellent agreement with analyses by Takazato & Kitahara and Tahir-Kheli & Elliott. In a separate calculation the tracer correlation factor in the same model was calculated using a Monte Carlo method analogous to the experimental method used for measuring diffusion isotope effects. Good agreement was obtained with the direct method, indicating that in this model the tracer correlation factor could be well represented by the impurity correlation factor form.

Diffusion Correlation and Isotope Effects in High-Defect-Content Solids. G.E.Murch: Philosophical Magazine A, 1984, 49[1], 21-9