[1] Univ Saskatchewan, Dept Chem, Saskatoon, SK S7N 5C9, Canada
[2] Univ Toulouse 3, Lab Math Emile Picard, CNRS UMR 5580, UFR MIG, F-31062 Toulouse 4, France
[3] Dalhousie Univ, Dept Math & Stat, Halifax, NS B3H 3J5, Canada
[4] Mem Univ Newfoundland, Dept Chem, Canada Res Chair Sci Modeling & Simulat, St Johns, NF A1B 3X7, Canada