Since the calculation of the correction potentials, which act on all particles, is computationally demanding, a parallelization of the LEUS routine using MPI was introduced, alongside the existing distributed-memory routines for the non-bonded interactions and the SHAKE algorithm for the solvent. To this purpose, a LEUS instance was initialized on each processor and assigned N/P particles, which are coupled to this potential. The CG and CG+B schemes show a comparable performance for up to 16 processors (Fig. ). Increasing the number of cores further, the tasks become more and more fine-grained, and the timings become dominated by the communication overhead. The pairwise interaction calculation benefits from additional resources up to 48 processors until the performance saturates. The CG box exhibits a linear scaling with up to 8 cores, which is an inherent limitation to the scaling of GROMOS for comparable numbers of atoms.