Chronus quantum: The next generation relativistic theory and quantum dynamics open-source package

The Chronus Quantum (ChronusQ) software package is an open-source software infrastructure which targets the solution of challenging problems that arise in ab initio electronic structure theory. Special emphasis is placed on the consistent treatment of time dependence, relativistic effect, many-body correlation, electron-nuclear coupling, and spin in the electronic wave function. In addition, ChronusQ provides support for the inclusion of uniform finite magnetic fields as external perturbations through the use of gauge-including atomic orbitals.
ChronusQ is a parallel electronic structure code written in modern C++ which utilizes both message passing implementation and shared memory (OpenMP) parallelism with the support of the TiledArray tensor engine. In addition to the examination of the current state of code base itself, a discussion regarding ongoing developments and developer contributions will also be provided. ChronusQ can be easily adopted by a wide user community, is well-designed and well-documented to promote reusability, composability, and maintainability, and relies on established, standardized tools to ensure sustainability.