In the current study we evaluate the use of a dumped shifted force electrostatic interaction model for the study of the structural properties of indium oxide and tin-doped indium oxide (ITO). This model is found to be computationally efficient and accurate in the calculations. More specifically.. the ion positions of In2O3, the preference of b-sites In substitution with Sir and the lattice constant of ITO anomalous dependency on Sn content varying from 3% to 6% calculated with this model agree with the experimental data and other theoretical first principle studies. For Sn content higher than 6% the calculated data deviate from the experimentally observed as the existence of the In4Sn3O12 phase was not taken into account. Also, we found an agreement to the Vegard's law of the lattice constant with simple In substitution with Sn ions. Finally the bulk modulus calculated for the ITO (92-97 GPa) is in good agreement with experimental data for ITO films. (c) 2007 Elsevier B.V. All rights reserved.