A new massively parallel version of CRYSTAL for large systems on High Performance Computing Architectures

Fully ab initio treatment of complex solid systems needs computational software able to efficiently take advantage of the growing power of High Performance Computing (HPC) architectures. Recent improvements in CRYSTAL, a periodic ab initio code that uses a Gaussian basis set, allows treatment of very large unit cells for crystalline systems on HPC architectures with high parallel efficiency in terms of CPU time and memory requirements. The latter is a crucial point, due to the trend towards architectures relying on a very high number of cores with associated relatively low memory availability. An exhaustive performance analysis shows that density functional calculations, based on a hybrid functional, of low-symmetry systems containing up to 100000 atomic orbitals and 8000 atoms are feasible on the most advanced HPC architectures available to European researchers today, using thousands of processors.