Klavsen Ehlers (salecone9)

We present the implementation of excited state Born-Oppenheimer molecular dynamics (BOMD) using a polarizable QM/MM approach based on a time-dependent density functional theory (TDDFT) formulation and the AMOEBA force field. The implementation relies on an interface between Tinker and Gaussian software and it uses an algorithm for the calculation of QM/MM energy and forces which scales linearly with the number of MM atoms. The resulting code can perform TDDFT/AMOEBA BOMD simulations on real-life systems with standard computational resources. As a test case, the method is applied to the study of the mechanism of locally-excited to charge-transfer conversion in dimethylaminobenzonitrile in a polar solvent. Our simulations confirm that such a conversion is governed by the twisting of the dimethylamino group which is accompanied by an important reorientation of solvent molecules.Alloying tin into lead-based halide perovskites is one of the strategies to reduce the chemical toxicities associated with lead-containing compounds, while retaining comparable physical properties. However, tin-based compounds possess their own shortcomings, with the most critical ones being their increased thermodynamic tendencies towards oxidative degradation, as well as vibrational anharmonicities due to the presence of shallow Sn-5s2 lone-pair electrons. Hereby, we performed density-functional-theory calculations to systematically examine the composition-dependent chemical and structural stabilities for Cs(PbxSn1-x)X3 (X = Cl, Br and I) alloys. We found that oxidative degradation to rhombohedral Cs2SnX6, SnO2 and cubic CsSnX3 tends to be the most favored pathway with no observable composition-dependent 'bowing behaviour', the latter is primarily governed by the bowing-effects in the demixing energies which are generated when the perovskite alloy phase-segregates into the two cubic end-members, which are two orders of magnitude smaller. Potential surface energy scans for the off-center B-site ion displacements further reveal the nonlinearity in the change of vibrational anharmonicity with respect to a linear change of Sn concentrations. Such nonlinearity is strongly modulated by the nature of the halide ions, in order to minimize the exchange repulsion between the charge densities of Sn-5s2 lone pairs and the octahedrally coordinating halogen anions.The sudden outbreak of a novel coronavirus in 2019 in Wuhan, China, that rapidly provoked a global concern, marked as the third attack of corona virus in the human society that affected the global healthcare system as well as the global economy. Until and unless an effective vaccine is discovered against the virus, the pharmacological intervention by different antivirals is in the run for remedy. The aim of this systematic review was to evaluate the role of favipiravir along with its safety and efficacy for the patients who are suffering from severe acute respiratory distress syndrome due to CoronaVirus-2 (SARS-CoV-2) as re-purposeful use. We searched PubMed, EMBASE for randomized controlled trials (RCTs), cilicaltrial.com for registered on going trails to evaluate the pros and cons of using favipiravir in COVID-19. After vigorous searching, screening and sorting of 314 articles for completed and published scientific evidences in electronic database, there were only 2 completed and published randomized control trials (RCT) and 17 ongoing or unpublished trials found until June 2020. The main outcome measures were viral clearance, clinical improvement and adverse events reported and published on 147 patients infected with SARS-CoV2. The 2 completed RCTs showed significantly better treatment effects on disease progression, viral clearance, improved the latency to relief for pyrexia and cough on favipiravir treated patients. Adverse effects caused Favipiravir are mild and manageable. Although 9 more RCTs and cohort studies are supposed to be completed by this time that may unveil some evidence for use of anti-