GCEED

Grid-based Coupled Electron and Electromagnetic field Dynamics (GCEED) is an open-source software package for massively parallel first-principles calculations of electron dynamics in real time and real space. The program codes are written in the Fortran 90/95 language with MPI and OpenMP. Time dependent density functional theory (TD-DFT) calculations can be performed on 100,000 CPU cores of K Computer with high parallel efficiency.