Implementation of Fragment Orbital Method (FMO) for Highly Parallelized Quantum Chemical Calculations with CP2K

The reported work aims at implementation of a method allowing realistic simulation of large or extra-large biochemical systems (of 106 to 107 atoms) with first-principle quantum chemical methods. The current methods treat the whole system simultaneously. In this way the comput time increases rapidly with the size of the system and does not allow efficient parallelization of the calculations due to the mutual interactions between the electron density in all parts of the system. In order to avoid these problems we implemented a version of the Fragment Orbital Method (FMO) in which the whole system is divided into fragments calculated separately. This approach assures nearly linear scaling of the compute time with the size of the system and provides efficient parallelization of the job. The work includes development of pre- and post-processing components for automatic division of the system into monomers and reconstructing of the total energy and electron density of the whole system