Biological complexes, structured ensembles of proteins or proteins/nucleic acids, perform many vital cellular functions, such as gene transcription, protein synthesis or regulation of cellular transport, and dysfunctions of those result in severe diseases. In order to understand diseases and develop treatments, the functional mechanisms of these biological complexes need to be elucidated. A crucial step in this process is the characterization of the structure and dynamics of these complexes. As large complexes are difficult to study by X-ray crystallography, alternative low-resolution experimental techniques such as cryo-electron microscopy, small angle X-ray scattering and fluorescence resonance energy transfer are often used to characterize their conformational states. Additionally, new experimental developments of X-ray Free Electron Lasers (XFEL, such as in SPring 8, RIKEN) should provide structural information close to atomic resolution. Our goal is to develop computational methods to obtain atomic level description of the functional states of biological complexes. Such methods will rely on the integration of various experimental data such as high resolution X-ray crystallography, lower resolution cryo-EM and emerging near atomic resolution XFEL with computational modeling through high performance computing such as with the supercomputers K and Fugaku. In addition, we aim to collaborate with experimental groups and the pharmaceutical industry to elucidate functional mechanism of biological systems.