1. Laboratory of Physics and Helsinki Institute of Physics, Helsinki University of Technology, Finland
2. Biophysics and Statistical Mechanics Group, Laboratory of Computational Engineering, Helsinki University of Technology, Finland, and Department of Biophysics, Jagiellonian University, Kraków, Poland
3. Department of Biophysics, Jagiellonian University, Kraków, Poland
4. Department of Applied Mathematics, The University of Western Ontario, London, ON, Canada
5. Institute of Physics, Tampere University of Technology, Finland, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, and Laboratory of Physics and Helsinki Institute of Physics, Helsinki University of Technology, Finland