Langevin dynamics (LD) simulations in Gromacs 5.1 in NVT ensemble are performed. The friction constant is set to 1.0 ps -1 . The stochastic processes correspond to the temperature T = 298 K. The time step of the velocity Verlet integrator is set to 7.5 fs. Together with the reduced molar mass 8.635 g mol -1 of all coarse-grained particles, the polymer conformations are sampled effectively. The electrostatic potential is computed using particle mesh Ewald method. To efficiently employ this method in a system with a low particle density, the value of a cut-off distance in the real space and the number of grid points in the Fourier reciprocal space are optimized, as described in Table .