A fingerprint based metric for measuring similarities of crystalline structures

Measuring similarities/dissimilarities between atomic structures is important for the exploration of potential energy landscapes. However, the cell vectors together with the coordinates of the atoms, which are generally used to describe periodic systems, are quantities not suitable as fingerprints to distinguish structures. Based on a characterization of the local environment of all atoms in a cell we introduce crystal fingerprints that can be calculated easily and allow to define configurational distances between crystalline structures that satisfy the mathematical properties of a metric. This distance between two configurations is a measure of their similarity/dissimilarity and it allows in particular to distinguish structures. The new method is an useful tool within various energy landscape exploration schemes, such as minima hopping, random search, swarm intelligence algorithms and high-throughput screenings

Novel polymorphs and polytypes of lithium chloride from structure predictions based on charge equilibration via neural network technique

By an extensive structural search using the minima hopping method together with the charge equilibration via neural network technique (CENT) artificial neural network potential, we find several novel lithium chloride structures. Besides reproducing the known low energy phases of LiCl, the structural search reveals 86 new phases of which 42 are energetically lower than the rocksalt phase. We classify our structures based on their structural similarities. While many of them can be considered as polytypes of known structures, there are also entirely unexpected low-density polymorphs that contain empty cages and channels

Retraction notice to �A survey of the secondary exposure to organophosphate and organochlorine pesticides and the impact of preventive factors in female villagers� Chem. 240 (2020) 124887(S0045653519321265)(10.1016/j.chemosphere.2019.124887)

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors and Editor-in-Chief. This paper has been retracted because the authors have found numerous errors in their method used for the analysis of the various pesticides. The extent of the errors is too large to make a simple correction possible. © 2020 Elsevier Lt

A survey of the secondary exposure to organophosphate and organochlorine pesticides and the impact of preventive factors in female villagers

Organophosphates (OPs) and organochlorine pesticides (OCPs) are two main types of pesticides that are widely used worldwide, and their toxicities have been reported in high-risk individuals, such as farmers and their wives. The aim of this study was to evaluate the levels of mentioned pesticides in farmers' wives (FWs) and compare them with the control group; we also aimed to assess the effect of personal health factors on the biochemical parameters. This case-control study was conducted on two FWs and control groups, consisting of 124 and 62 individuals, respectively. Serum levels of OCPs were measured using gas chromatography (GC) method. In addition, the activity of acetylcholine esterase (AChE), total antioxidant capacity (TAC), and serum levels of malondialdehyde (MDA) were evaluated in all participants. Additionally, the observance of personal health guidelines was assessed. Serum levels of OCPs in the FWs group were significantly higher than the controls. In addition, AChE activity in FWs was significantly lower than the controls. Moreover, it was found that higher levels of education lead to a better observation of most individual health guidelines, which results in reducing the biological adverse effects of pesticides. The results of this study indicated that the use of OCPs, as an illegal pesticide with known toxic and carcinogenic effects, has spread to southern Iran, which may have biological toxic effects. Also, observing the personal health points significantly reduced these complications and it is, therefore, recommended that more attention should be paid to this issue. Copyright © 2019 Elsevier Ltd. All rights reserved

Two-Dimensional Hexagonal Sheet of TiO2

We report the ab initio discovery of a novel putative ground state for quasi two-dimensional TiO2 through a structural search using the minima hopping method with an artificial neural network potential. The structure is based on a honeycomb lattice and is energetically lower than the experimentally reported lepidocrocite sheet by 7 meV/atom and merely 13 meV/atom higher in energy than the rutile bulk structure. According to our calculations, the hexagonal sheet is stable against mechanical stress, chemically inert, and can be deposited on various substrates without disrupting the structure. Its properties differ significantly from all known TiO2 bulk phases with a large gap of 5.05 eV that can be tuned through strain and defect engineering

Nano‐Scale Complexions Facilitate Li Dendrite‐Free Operation in LATP Solid‐State Electrolyte

Dendrite formation and growth remains a major obstacle toward high-performance all solid-state batteries using Li metal anodes. The ceramic Li(1+x)Al(x)Ti(2−x)(PO4)3 (LATP) solid-state electrolyte shows a higher than expected stability against electrochemical decomposition despite a bulk electronic conductivity that exceeds a recently postulated threshold for dendrite-free operation. Here, transmission electron microscopy, atom probe tomography, and first-principles based simulations are combined to establish atomistic structural models of glass-amorphous LATP grain boundaries. These models reveal a nanometer-thin complexion layer that encapsulates the crystalline grains. The distinct composition of this complexion constitutes a sizable electronic impedance. Rather than fulfilling macroscopic bulk measures of ionic and electronic conduction, LATP might thus gain the capability to suppress dendrite nucleation by sufficient local separation of charge carriers at the nanoscale