Mckenziemelchiorsen7221

We propose a simple direct-sum method for the efficient evaluation of lattice sums in periodic solids. It consists of two main principles (i) the creation of a supercell that has the topology of a Clifford torus, which is a flat, finite, and borderless manifold; (ii) the renormalization of the distance between two points on the Clifford torus by defining it as the Euclidean distance in the embedding space of the Clifford torus. Our approach does not require any integral transformations nor any renormalization of the charges. We illustrate our approach by applying it to the calculation of the Madelung constants of ionic crystals. We show that the convergence toward the system of infinite size is monotonic, which allows for a straightforward extrapolation of the Madelung constant. We are able to recover the Madelung constants with a remarkable accuracy, and at an almost negligible computational cost, i.e., a few seconds on a laptop computer.The novel coronavirus (2019-nCoV) spike protein is a smart molecular machine that instigates the entry of coronavirus to the host cell causing the COVID-19 pandemic. In this study, a symmetry-information-loaded structure-based Hamiltonian is developed using recent Cryo-EM structural data to explore the complete conformational energy landscape of the full-length prefusion spike protein. The study finds the 2019-nCoV prefusion spike to adopt a unique strategy by undertaking a dynamic conformational asymmetry that results in two prevalent asymmetric structures of spike where one or two spike heads rotate up to provide better exposure to the host-cell receptor. A few unique interchain interactions are identified at the interface of closely associated N-terminal domain (NTD) and receptor binding domain (RBD) playing a crucial role in the thermodynamic stabilization of the up conformation of the RBD in the case of the 2019-nCoV spike. The interaction-level information decoded in this study may provide deep insight into developing effective therapeutic targets.Interphase engineering is becoming increasingly important in improving the electrochemical performance of cathode materials for rechargeable batteries, including Li ion, Li metal, and all-solid-state batteries, because irreversible surface reactions, such as electrolyte decomposition, and transition metal dissolution, constitute one of these batteries' failure modes. In this connection, various surface-engineered cathode materials have been investigated to improve interfacial properties. No synthesis methods, however, have considered a plane-selective surface modification of cathode materials. Herein, we introduce the basal-plane-selective coating of Li2SnO3 on layered Li[Ni x Co1-x]O2 (x = 0 and 0.5) using the concept of the thermal phase segregation of Sn-doped Li[Ni x Co1-x]O2 due to the solubility variation of Sn in Li[Ni x Co1-x]O2 with respect to temperature. The plane-selective surface modification enables the formation of Li2SnO3 nanolayers on only the Li[Ni x Co1-x]O2 basal plane without hindering the charge transfer of Li+ ions. As a result, the vertical heterostructure of Li[Ni x Co1-x]O2-Li2SnO3 core-shells show promising electrochemical performance.The current pandemic demands a search for therapeutic agents against the novel coronavirus SARS-CoV-2. Here, we present an efficient computational strategy that combines machine learning (ML)-based models and high-fidelity ensemble docking studies to enable rapid screening of possible therapeutic ligands. Targeting the binding affinity of molecules for either the isolated SARS-CoV-2 S-protein at its host receptor region or the S-proteinhuman ACE2 interface complex, we screen ligands from drug and biomolecule data sets that can potentially limit and/or disrupt the host-virus interactions. Top scoring one hundred eighty-seven ligands (with 75 approved by the Food and Drug Administration) are further validated by all atom docking studies. Important molecular descriptors (2χ n , topological surface area, and ring count) and promising chemical fragments (oxolane, hydroxy, and imidazole) are identified to guide future experiments. Overall, this work expands our knowledge of small-molecule treatment against COVID-19 and provides a general screening pathway (combining quick ML models with expensive high-fidelity simulations) for targeting several chemical/biochemical problems.Photoinduced proton-coupled electron transfer (PCET) in anthracene-phenol-pyridine triads exhibits inverted region behavior, where the more thermodynamically favorable process is slower. The long-lived transient charge-separated state (CSS) associated with electron transfer from phenol to anthracene and inverted region behavior were only observed experimentally for certain triads. Herein, excited state molecular dynamics simulations were performed on four different triads to simulate the nonequilibrium dynamics following photoexcitation to the locally excited state (LES) of anthracene. These simulations identified two distinct PCET pathways the triads exhibiting inverted region behavior transitioned from the LES to the CSS, whereas the other triads transitioned to a local electron-proton transfer (LEPT) state within phenol and pyridine. The simulations suggest that PCET to the LEPT state is slower than PCET to the CSS and provides an alternative relaxation pathway. The mechanistic pathways, as well as the time scales of the electron and proton transfers, can be controlled by tuning the substituents.The discharge process of a nonaqueous Li-O2 battery at the cathode is the direct oxygen reduction reaction (ORR) with the formation of discharge product, e.g., Li2O2, deposits on the cathode surface. The aggressive superoxide intermediate generated during the ORR severely degrades the organic electrolyte and carbon-based cathodes. To avoid the formation of superoxide species and promote the growth of Li2O2 in the electrolyte solution, we employ a soluble cobaltocene [Co(C5H5)2, Cp2Co] as a homogeneous molecule catalyst to boost the discharge performance of Li-O2 batteries. Owing to the unique chemical reactivity of Cp2Co with molecular oxygen, the electrochemistry of the discharge process at the cathode is the (Cp2Co)2II-O22- adduct-mediated process rather than direct electrochemical oxygen reduction, thereby avoiding the formation of aggressive superoxide intermediate. see more In addition, the strong intermolecular attraction between Cp2Co and the newly formed Li2O2 promotes the solution phase growth of Li2O2, which effectively suppresses electrode passivation.