Electrolyte solutions in alkaline nuclear waste contain aluminate, hydroxide, nitrate and nitrite with sodium as the predominant counterion. The salts of these ions are highly soluble, so the liquids are highly concentrated. This study found that there is a substantial incompatibility between the...

The recently developed real-time nuclear–electronic orbital (RT-NEO) approach provides an elegant framework for treating electrons and selected nuclei, typically protons, quantum mechanically in nonequilibrium dynamical processes. However, the RT-NEO approach neglects the motion of the other nuclei...

Understanding the reactivity behavior of aluminum oxyhydroxide phases, widely present in nuclear waste tanks, in radiation environments is essential to develop better nuclear waste processing approaches. Recent experiments using vibrational sum frequency generation, a surface sensitive technique...

Determining kinetic parameters such as activation energy (Ea), pre-exponential factor (A), rate constants, and reaction order (n) via thermal analysis techniques is important to material synthesis and fabrication, industrial production, biomedicals, energy storage, catalysis, etc. Various kinetic...

Real-time electronic structure methods provide an unprecedented view of electron dynamics and ultrafast spectroscopy on the atto- and femtosecond time scale with vast potential to yield new insights into the electronic behavior of molecules and materials. In this Review, we discuss the fundamental...

Silica-encapsulated gold core@shell nanoparticles (Au@SiO2 CSNPs) were synthesized via a tunable bottom-up procedure to catalyze the aerobic oxidation of benzyl alcohol. The nanoparticles exhibit a mesoporous shell which enhances selectivity by inhibiting the formation of larger species. Adding...

X-ray, energetic photon, and electron irradiation can ionize and electronically excite target atoms and molecules. These excitations undergo complicated relaxation and energy-transfer processes that ultimately determine the manifold system responses to the deposited excess energy. In weakly bound...

The role of oligomeric aluminate species in the precipitation of aluminum (Al) phases such as gibbsite (α-Al(OH)3) from aqueous hydroxide solutions remains unclear and difficult to probe directly, despite its importance for developing accurate predictions of Al solubility in highly alkaline systems...

The iron oxy-hydroxide lepidocrocite (𝛾γ-FeOOH) is an abundant mineral critical to a number of chemical and technological applications. Of particular interest are the ground state and finite temperature magnetic order and the subsequent impact this has upon crystal properties. The magnetic...

The accurate description of excited vibronic states is important for modeling a wide range of photoinduced processes. The nuclear–electronic orbital (NEO) approach, which treats specified protons on the same level as the electrons, can describe excited electronic–protonic states. Herein the...

Nitrite (NO2−) is a prevalent nitrogen oxyanion in environmental and industrial processes, but its behavior in solution, including ion pair formation, is complex. This solution phase complexity impacts industries such as nuclear waste treatment, where NO2− significantly affects the solubility of...

Understanding the structure and composition of aluminate complexes in extremely alkaline systems such as Bayer liquors has received enormous attention due to their fundamental and industrial importance. However, obtaining direct molecular information of the underlying ion–ion interactions using...

The theoretical prediction of x-ray absorption spectra (XAS) has become commonplace in electronic structure theory. The ability to better model and understand L-edge spectra is of great interest in the study of transition metal complexes and a wide variety of solid state materials. However, until...

The recent development of the Ehrenfest dynamics approach in the nuclear-electronic orbital (NEO) framework provides a promising way to simulate coupled nuclear-electronic dynamics. Our previous study showed that the NEO-Ehrenfest approach with a semiclassical traveling proton basis method yields...

Understanding the origin of reactive species following ionization in aqueous systems is an important aspect of radiation–matter interactions as the initial reactive species lead to production of radicals and subsequent long-term radiation damage. Tunable ultrafast X-ray free-electron pulses provide...