The proposed development work in this theoretical cross-cutting staff proposal include: (1) Development of new algorithms supporting high-level electron structure calculation of reaction mechanisms involving charge transfer (e.g., electron transfer and proton exchange reactions in partially hydrated mineral surfaces). This software will support the prediction of the mechanisms of electron transfer, the structure of defects in oxides and identify charge transfer mechanisms occurring at the mineral water interface. (2) Development of simulation methods for the interpretation of IR and Raman of the fluid and interface structures. (3) Explore machine learning methods to efficiently sample fluid and interface structure. This software will support proposed EXAFS analysis studies with Rosso and Ilton (EMSL users), as well as other current and future interpretations of vibrational and x-ray spectroscopies in the project. (4) Improving the performance and usability of our codes for geochemistry and environmental researchers, including the continued development of reaction path searching methods. (5) In collaboration with Bagus, develop Software and Modeling strategies to Support Mossbauer Spectroscopy Interpretation (EMSL experimental capability).