Static Subspace Approximation for Random Phase Approximation Correlation Energies: Implementation and Performance.

Developing theoretical understanding of complex reactions and processes at interfaces requires using methods that go beyond semilocal density functional theory to accurately describe the interactions between solvent, reactants and substrates. Methods based on many-body perturbation theory, such as the random phase approximation (RPA), have previously been limited due to their computational complexity. However, this is now a surmountable barrier due to the advances in computational power available, in particular through modern GPU-based supercomputers.

Insights into Electrochemical CO Reduction on Metallic and Oxidized Tin Using Grand-Canonical DFT and In Situ ATR-SEIRA Spectroscopy.

Electrochemical CO reduction (COR) to formate is an attractive carbon emissions mitigation strategy due to the existing market and attractive price for formic acid. Tin is an effective electrocatalyst for COR to formate, but the underlying reaction mechanism and whether the active phase of tin is metallic or oxidized during reduction is openly debated. In this report, we used grand-canonical density functional theory and attenuated total reflection surface-enhanced infrared absorption spectroscopy to identify differences in the vibrational signatures of surface species during COR on fully metallic and oxidized tin surfaces.

Activating Nitrogen for Electrochemical Ammonia Synthesis via an Electrified Transition-Metal Dichalcogenide Catalyst.

The complex interplay between local chemistry, the solvent microenvironment, and electrified interfaces frequently present in electrocatalytic reactions has motivated the development of quantum chemical methods that can accurately model these effects. Here, we predict the thermodynamics of the nitrogen reduction reaction (NRR) at sulfur vacancies in 1T'-phase MoS and highlight how the realistic treatment of potential within grand canonical density functional theory (GC-DFT) seamlessly captures the multiple competing effects of applied potential on a catalyst interface interacting with solvated molecules. In the canonical approach, the computational hydrogen electrode is widely used and predicts that adsorbed N structure properties are potential-independent.

Computationally Predicted High-Throughput Free-Energy Phase Diagrams for the Discovery of Solid-State Hydrogen Storage Reactions.

The design of multinary solid-state material systems that undergo reversible phase changes via changes in temperature and pressure provides a potential means of safely storing hydrogen. However, fully mapping the stabilities of known or newly targeted compounds relative to competing phases at reaction conditions has previously required many stringent experiments or computationally demanding calculations of each compound's change in Gibbs energy with respect to temperature, (). In this work, we have extended the approach of constructing chemical potential phase diagrams based on Δ() to enable the analysis of phase stability at non-zero temperatures.

Inorganic Halide Double Perovskites with Optoelectronic Properties Modulated by Sublattice Mixing.

All-inorganic halide double perovskites have emerged as a promising class of materials that are potentially more stable and less toxic than lead-containing hybrid organic-inorganic perovskite optoelectronic materials. In this work, 311 cesium chloride double perovskites (Cs'Cl) were selected from a set of 903 compounds as likely being stable on the basis of a statistically learned tolerance factor (τ) for perovskite stability. First-principles calculations on these 311 double perovskites were then performed to assess their stability and identify candidates with band gaps appropriate for optoelectronic applications.

Highly dispersed Co deposited on AlO particles via CoCp + H ALD.

Highly dispersed cobalt atoms were deposited on porous alumina particles using atomic layer deposition (ALD) with a CoCp/H chemistry at approximately 7 wt%. H did not completely reduce the cyclopentadienyl organic ligands bound to deposited Co atoms at ALD reaction conditions. A sharp decline in Co deposited per cycle for two or more ALD cycles indicates that much of the AlO surface is sterically blocked from further CoCp deposition after the first CoCp exposure.

A three-dimensional spheroidal cancer model based on PEG-fibrinogen hydrogel microspheres.

Three-dimensional (3D) in vitro cancer models offer an attractive approach towards the investigation of tumorigenic phenomena and other cancer studies by providing dimensional context and higher degree of physiological relevance than that offered by conventional two-dimensional (2D) models. The multicellular tumor spheroid model, formed by cell aggregation, is considered to be the "gold standard" for 3D cancer models, due to its ease and simplicity of use. Although better than 2D models, tumor spheroids are unable to replicate key features of the native tumor microenvironment, particularly due to a lack of surrounding extracellular matrix components and heterogeneity in shape, size and aggregate forming tendencies.

Polymeric Biomaterials for In Vitro Cancer Tissue Engineering and Drug Testing Applications.

Biomimetic polymers and materials have been widely used in tissue engineering for regeneration and replication of diverse types of both normal and diseased tissues. Cancer, being a prevalent disease throughout the world, has initiated substantial interest in the creation of tissue-engineered models for anticancer drug testing. The development of these in vitro three-dimensional (3D) culture models using novel biomaterials has facilitated the investigation of tumorigenic and associated biological phenomena with a higher degree of complexity and physiological context than that provided by established two-dimensional culture models.