i-PI 2.0: a universal force engine for advanced molecular simulations by Kapil, V, Rossi, M, Marsalek, O, Petraglia, R, Litman, Y, Spura, T, Cheng, B, Cuzzocrea, A, Meißner, R, Wilkins, D, Helfrecht, B, Juda, P, Bienvenue, S, Fang, W, Kessler, J, Poltavsky, I, Vandenbrande, S, Wieme, J, Corminboeuf, C, Kühne, T, Manolopoulos, D, Markland, T, Richardson, J, Tkatchenko, A, Tribello, G, Van Speybroeck, V, Ceriotti, M