1. Department of Mathematics, Aston University, Birmingham B4 7ET, U.K.
2. Laboratory for Computational Molecular Design, RIKEN Center for Biosystems Dynamics (BDR), Building B, 6-2-4 Furuedai, Suita, Osaka 565-0874, Japan
3. Immanuel Kant Baltic Federal University, A. Nevskogo str. 14, Kaliningrad 236041, Russian Federation