Massively Parallel Computing
For calculations made in the previous section, the input files for the fragments were submitted to one specified queue, and each corresponded to an independent job ID. Additionally, it is possible to submit MFCC jobs by interfacing with the LSSCF module of BDF42,44,86-88 and X-Pol.42 In the present study, we used GridMol version 2.0 to supply the fragmentation scheme (e.g., monomers and metal-ligand dimers) and then interfaced with the X-Pol package for massively parallel calculations using the LSSCF module in the BDF package. This allowed the hybrid MPI/OpenMP scheme to be used for accelerating the calculations according to optimized load-balance and task-tracking. Due to limited computing resources, we selected only part of 3FMH system, including 1020 atoms, for testing using PBE and STO-3G as the functional and basis set, respectively. Table 2 shows the acceleration ratio of 49,152 cores relative to 12,288 cores at 53%, indicating the fragment-based method as a better choice for large molecule systems according to accuracy and efficiency.