The benchmarks based on the B3LYP XC functional show that the use of two task groups extends the scaling to 1,728 cores (see Fig. ). The scaling is limited by the fact that the number of orbitals in this system is a relatively small prime number (47), which inevitably leads to load imbalance of the exact exchange computation that in turn constitutes the bottleneck of the calculation both with respect to execution time and parallelization. Finally, enforcing the orbital orthogonality constraint of the CP-MD on each time step, even though it is parallelized, may further hamper scaling of a pure CP-MD run. Therefore, the maximum achievable performance for B3LYP simulations was 15.88 second per time step of BO-MD and 2.00 seconds per time step for CP-MD.