k wall and β determine the strength and steepness of the potential, respectively and we use the values suggested by Grimme (k wall = 0.019E h and β = 10 Bohr -1 ). r i is the position vector of atom i and R is the radius of the sphere, which is related to the input coordinates by a scaling-factor s. The simulations are run for 50 ps with 0.4 fs time steps, a thermostat temperature of 300 K, double hydrogen weight and with no bonds constrained (SHAKE off) unless otherwise noted. A maximum of 100 structures (n) are used for the RMSD criteria.