Evaluation of point defect equilibria in Hg0.8Cd0.2Te and Hg0.6Cd0.4Te using the Gibbs free energy minimization approach is demonstrated in this paper. Appropriate standard Gibbs free energies of formation for doubly charged mercury vacancy, mercury interstitial, electron and hole were derived. Thep‐ntransition behavior in Hg0.8Cd0.2Te and Hg0.6Cd0.4Te with intrinsic defects and/or residual impurity donors was also calculated and compared favorably with experimental data from literature.