A semi-empirical calculation of the orbital energy levels of CuF6-4has been performed using the Wolfsberg-Helmholz approximations as extended by Ballhausen and Gray. The calculated value of 10Dqis rather insensitive to the initial assumptions and is in good agreement with experiments. The location of the ‘non-bonding’t1ulevel is on the other hand found to be very dependent upon the atomic wavefunctions used.