Local electronic structure in aLiAlO2single crystal studied withLi7NMR spectroscopy and comparison with quantum chemical calculations

2006 ◽  
Vol 74 (24) ◽  
Author(s):  
Sylvio Indris ◽  
Paul Heitjans ◽  
Reinhard Uecker ◽  
Thomas Bredow
Keyword(s):  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Local Electronic Structure

scholarly journals Conformational behavior and electronic structure of silylketenes studied with quantum chemical calculations and photoelectron spectroscopy

1997 ◽  
Vol 75 (12) ◽  
pp. 1851-1861 ◽  
Author(s):  
Heidi M. Muchall ◽  
Nick H. Werstiuk ◽  
Jiangong Ma ◽  
Thomas T. Tidwell ◽  
Kuangsen Sung
Keyword(s):  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Photoelectron Spectroscopy ◽  
Quantum Chemical ◽  
Computational Study ◽  
Photoelectron Spectra ◽  
Conformational Behavior ◽  
Torsional Angle ◽  
Orbital Interaction ◽  
Orbital Energies

The He(I) photoelectron spectra of silylketenes (Me3Si)2C=C=O (1), Me5Si2CH=C=O (2), Me2Si(CH=C=O)2 (3), MeSi(CH=C=O)3 (4), (SiMe2CH=C=O)2 (5), and (CH2SiMe2CH=C=O)2 (6) have been recorded and their structures and orbital energies have been calculated by ab initio methods. Orbital energies for disilanes 2 and 5 are strongly dependent on a Si-Si-C-C torsional angle due to σ–π orbital interaction. Comparisons between experimental and simulated spectra show that 2 and 5 prefer conformations in which the Si—Si bond and ketene group(s) are approximately orthogonal (113° and 111°, respectively). Silylalkenes Me5Si2CH=CH2 (7) and (SiMe2CH=CH2)2 (8), which have been included in the computational study, show the same behavior as their corresponding silylketenes. Silylbis- and trisketenes 3–6 do not exhibit π–π interaction of any significance. For Si—Si containing compounds, the best agreement between experimental and computed data was obtained when Becke3LYP/6-31G*//HF/3-21G* was employed. Keywords: conformational behavior, electronic structure, photoelectron spectroscopy, quantum chemical calculations, silylketenes.

Crystal and electronic structure of the new ternary phosphide Ho5Pd19P12

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Olha Zhak ◽  
Oksana Karychort ◽  
Volodymyr Babizhetskyy ◽  
Chong Zheng
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Structure Property Relationships ◽  
Metallic Bonding ◽  
Crystal And Electronic Structure ◽  
Insight Into

Abstract The title compound was prepared from the pure elements by sintering. The crystal structure was investigated by means of powder X-ray diffraction data. Ho5Pd19P12 exhibits the hexagonal Ho5Ni19P12-type structure with space group P 6 ‾ 2 m $P‾{6}2m$ , a = 13.1342(2), c = 3.9839(1) Å, R I = 0.060, R p = 0.080. The crystal structure can be described as a combination of two types of the structural units, [HoPd6P3] and [Ho3Pd10P6], respectively, mutually displaced by 1/2 along the crystallographic c axis. Quantum chemical calculations have been performed to analyze the electronic structure and provide deeper insight into the structure-property relationships. The results of the quantum chemical calculations indicate that the material features metallic bonding between Ho and Pd and covalent bonding between Pd and P.

Electronic Structure and Optical Response of Electroluminescent Conjugated Polymers

1997 ◽  
Vol 488 ◽  
Author(s):  
J. L. Bredas ◽  
J. Cornil ◽  
D. Beljonne ◽  
D. A. Dos Santos ◽  
Z. Shuaiv ◽  
...  
Keyword(s):  
Experimental Data ◽  
Optical Properties ◽  
Electronic Structure ◽  
Quantum Yield ◽  
Conjugated Polymers ◽  
Quantum Chemical Calculations ◽  
Theoretical Approach ◽  
Quantum Chemical ◽  
Fluorescence Quantum Yield ◽  
Remarkable Agreement

AbstractIn this contribution, we investigate by means of correlated quantum-chemical calculations the influence of intermolecular interactions on the absorption and emission properties of conjugated chains. Various strategies are suggested to avoid a substantial decrease in fluorescence quantum yield in condensed media. Finally, the reliability of our theoretical approach is validated by showing the remarkable agreement obtained between the experimental data and the calculated optical properties of clusters formed by sexithienyl molecules.

scholarly journals Electronic structure at coarse-grained resolutions from supervised machine learning

2019 ◽  
Vol 5 (3) ◽  
pp. eaav1190 ◽  
Author(s):  
Nicholas E. Jackson ◽  
Alec S. Bowen ◽  
Lucas W. Antony ◽  
Michael A. Webb ◽  
Venkatram Vishwanath ◽  
...  
Keyword(s):  
Machine Learning ◽  
Electronic Structure ◽  
Quantum Chemical Calculations ◽  
Spatial Resolution ◽  
Quantum Chemical ◽  
Degrees Of Freedom ◽  
Soft Materials ◽  
Conformational Space ◽  
Supervised Machine Learning ◽  
Coarse Grained

Computational studies aimed at understanding conformationally dependent electronic structure in soft materials require a combination of classical and quantum-mechanical simulations, for which the sampling of conformational space can be particularly demanding. Coarse-grained (CG) models provide a means of accessing relevant time scales, but CG configurations must be back-mapped into atomistic representations to perform quantum-chemical calculations, which is computationally intensive and inconsistent with the spatial resolution of the CG models. A machine learning approach, denoted as artificial neural network electronic coarse graining (ANN-ECG), is presented here in which the conformationally dependent electronic structure of a molecule is mapped directly to CG pseudo-atom configurations. By averaging over decimated degrees of freedom, ANN-ECG accelerates simulations by eliminating backmapping and repeated quantum-chemical calculations. The approach is accurate, consistent with the CG spatial resolution, and can be used to identify computationally optimal CG resolutions.

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