libwfa: Wavefunction analysis tools for excited and open?shell electronic states

An open-source software library for wavefunction analysis, libwfa, provides a comprehensive and flexible toolbox post-processing excited-state calculations, featuring hierarchy of interconnected visual quantitative analysis methods. These tools afford compact graphical representations various processes, provide detailed insight into electronic structure, are suitable automated processing large data sets. The is based on reduced quantities, such as state transition density matrices (DMs), allows one to distill simple molecular orbital pictures physical phenomena from intricate correlated wavefunctions. implemented descriptors rigorous link between many-body wavefunctions intuitive chemical models, example, exciton binding, double excitations, relaxation, polyradical character. A broad range quantum-chemical methods interfaced with libwfa via uniform interface layer in the form DMs. This contribution reviews structure highlights its capabilities by several representative use cases. article categorized under: Software > Quantum Chemistry Theoretical Physical Spectroscopy