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Search query: quantum-mechanical predictions
50 articles match your search "quantum-mechanical predictions"Results 1 to 10, sorted by relevance:
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Histidine protonation is fraught, but a new quantum-mechanical method can provide insight into choices.
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A new interaction energy model for molecular dimers, CE-1p, accurately calculates intermolecular interactions in molecular crystals. Improved treatment of dispersion and polarization helps it outperform existing models with accuracy comparable to advanced DFT methods with only a single fitted parameter.
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A new crystallographic quantum-mechanical/molecular-mechanical model for the prediction of molecular crystal structures is described. Applications include polymorphic systems and molecules from the CCDC blind tests of crystal structure prediction.
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Ion radii are derived from observed mean bond lengths (characteristic bond lengths) for 135 ions bonded to oxygen, fluorine, hydroxyl, chlorine and nitrogen. Radii derived from quantum-mechanical calculations do not agree with radii derived from experimentally determined bond lengths. However, this problem is removed by recognition that ion radii determined from characteristic bond lengths are not a measure of the sizes of ions but proxy variables for characteristic bond lengths.
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Here, the n = 2 satellite present for manganese-containing materials and across materials science has been successfully observed by applying the new technique of extended-range high-energy-resolution fluorescence detection (XR-HERFD), developed from high-resolution resonant inelastic X-ray scattering and HERFD, and the spectra have been predicted with new advanced theory.
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A personal view on crystal structures is offered: past and present, ordered and disordered, static and dynamic, and problems solved and open.
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Dudek and coworkers [Acta Cryst. (2020), B76, 322–335] report an integrated X-ray powder diffraction, NMR crystallography and crystal structure prediction study to determine crystal structures that could not have been determined using a single method. This is an important example that nicely illustrates the process of combining techniques and demonstrates the importance of careful validation.
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For the first time, the use of experimentally derived molecular electron densities as ρB(r) in calculations based on frozen-density embedding theory (FDET) of environment-induced shifts of electronic excitations for chromophores in clusters is demonstrated. ρB(r) was derived from X-ray restrained molecular wavefunctions of glycylglycine to obtain environment densities for simulating electronic excitations in clusters.
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This article describes the joint refinement program MOLLYNX dedicated to spin-resolved electron density distribution. Multipole and atomic orbital models are described and applications for organic and inorganic magnetic materials are discussed.
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A new computational tool, CADEE (Computer-Aided Directed Evolution of Enzymes), is presented.