Mutual Transformations of Polysulfide Chromophore Species in Sodalite-Group Minerals: A DFT Study on S Decomposition.

It is known that various polysulfide species determine the color of sodalite-group minerals (haüyne, lazurite, and slyudyankaite), and that heating induces their transformations and color change, but the mechanisms of the transitions are unknown. A prominent example is the decay of cyclic S molecule. Using density-functional simulations, we explore its main decay pathways into the most probable final reaction products (the pairs of radical anions S⋅+S⋅ and S⋅+S⋅).

Lithiation of phosphorus at the nanoscale: a computational study of LiP clusters.

Systematic structure prediction of LiP nanoclusters was performed for a wide range of compositions (0 ≤ ≤ 10, 0 ≤ ≤ 20) using the evolutionary global optimization algorithm USPEX coupled with density functional calculations. With increasing Li concentration, the number of P-P bonds in the cluster reduces and the phosphorus backbone undergoes the following transformations: elongated tubular → multi-fragment (with mainly P rings and P cages) → cyclic topology → branched topology → P-P dumbbells → isolated P ions. By applying several stability criteria, we determined the most favorable LiP clusters and found that they are located in the compositional area between ≈ /3 and ≈ /3 + 6.

Prediction and Rationalization of Abundant C-N-H Molecules in Different Environments.

The extreme chemical diversity of CNH molecules is at the same time very important (central in organic chemistry) and difficult to rationalize in the sense that some molecules are abundant and easy to synthesize, while others are rare and difficult to make. Using the recently developed criteria of molecular "magicity", combined with evolutionary structure prediction and quantum-chemical calculations, we study these molecules in a wide range of compositions (0 ≤ ≤ 13, 0 ≤ ≤ 4, and 0 ≤ ≤ 14). "Magic" molecules are defined as those that are lower in energy than any isochemical mixture of molecules with the nearest compositions.

Ultralow reaction barriers for CO oxidation in Cu-Au nanoclusters.

Systematic structure prediction of CuAu nanoclusters was carried out for a wide compositional area ( + ≤ 15) using the evolutionary algorithm USPEX and DFT calculations. The obtained structural data allowed us to assess the local stability of clusters and their suitability for catalysis of CO oxidation. Using these two criteria, we selected several most promising clusters for an accurate study of their catalytic properties.

Stability of sulfur molecules and insights into sulfur allotropy.

Using evolutionary algorithm USPEX, we predict structures of sulfur molecules S ( = 2 - 21). It is shown that for ≥ 5 stable structures of sulfur molecules are closed helical rings, which is in agreement with the experimental data and previous calculations. We investigate the stability of molecules using the following criteria: second-order energy difference (Δ), fragmentation energy () and HOMO-LUMO gaps.