Quantum mechanical cluster calculations of ionic materials: revision 10 of the ab initio Perturbed Ion program

We present the 10th revision of the pi7 code, a program to calculate the electronic structure of ionic materials by means of the ab initio Perturbed Ion (aiPI) method. The program has been extensively optimized and partially vectorized since the last published version, significantly improving its performance. Two completely new modules have been incorporated into the main code. The first of them computes interionic potentials directly from the aiPI solution, and the second one introduces a semiclassical dipolar model contribution. The program has evolved into an easily portable code, while maintaining a friendly user interface. (C) 1997 Elsevier Science B.V.