1. Computer Modeling Group Inc., Calgary, AB T2L 2M1, Canada
2. Physical Sciences Department, MacEwan University, Edmonton, AB T5J 4S2, Canada
3. Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada
4. DIMEAS, Politecnico di Torino, 10129 Turin, Italy
5. Silesian University of Technology, 44-100 Gliwice, Poland