Wavefunction methods for X-ray processes
X-ray spectroscopy is an element-specific probe that can be used to study transition-metal enzymes and solution catalysts. With new experimental capabilities, it is now possible to collect high-resolution spectral data that directly probe electronic structure. This makes it important to use theoretical methods that include the important spectral effects. We have expanded the use of a method, based on multiconfigurational wavefunction theory, to simulate X-ray spectra of both closed and open-shell systems. With recent implementations of transition intensities beyond the electric dipole approximation, we have expanded our modeling capabilities to a range of new x-ray spectroscopic techniques. We can now model absorption, emission and scattering techniques that can be used on systems in their native environment, thus opening up new possibilities to understand chemical processes. Applications range from fingerprinting intermediates in enzymatic reactions to the electronic structure of metal-oxo systems capable of solar fuel catalysis.