Energy band dispersion calculations have been performed for Ag2CdI4 superionic within a framework of local density approximation (Perdew-Zunger parameterization) exploiting the first-principles CASTEP computer code. The ab-initio electronic structure simulations were performed for both (I (4) over bar and I (4) over bar 2m) types of epsilon-Ag2CdI4 crystalline structures. Principal optical functions as well as the density of electronic states in the spectral range of inter-band optical transitions (2.5 eV-20 eV) were determined. Theoretically calculated absorption coefficients derived from the obtained band structure are compared with appropriate experimental data. (C) 2010 Elsevier B.V. All rights reserved.