Crystal symmetry and pressure effects on the valence band structure ofγ-InSe andε-GaSe: Transport measurements and electronic structure calculations

2005 ◽  
Vol 71 (12) ◽  
Author(s):  
D. Errandonea ◽  
A. Segura ◽  
F. J. Manjón ◽  
A. Chevy ◽  
E. Machado ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Valence Band ◽  
Electronic Structure Calculations ◽  
Crystal Symmetry ◽  
Pressure Effects ◽  
Valence Band Structure ◽  
Transport Measurements ◽  
Structure Calculations

Magnetic Ground State and Electronic Structure Calculations of PbMnO3 Using DFT

2014 ◽  
Vol 895 ◽  
pp. 420-423 ◽  
Author(s):  
Sathya Sheela Subramanian ◽  
Baskaran Natesan
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Fermi Level ◽  
Ground State ◽  
Density Functional ◽  
Electronic Structure Calculations ◽  
Magnetic Ground State ◽  
Electronic Band ◽  
Structure Calculations ◽  
Centrosymmetric Structure

Structural optimization, magnetic ground state and electronic structure calculations of tetragonal PbMnO3have been carried out using local density approximation (LDA) implementations of density functional theory (DFT). Structural optimizations were done on tetragonal P4mm (non-centrosymmetric) and P4/mmm (centrosymmetric) structures using experimental lattice parameters and our results indicate that P4mm is more stable than P4/mmm. In order to determine the stable magnetic ground state of PbMnO3, total energies for different magnetic configurations such as nonmagnetic (NM), ferromagnetic (FM) and antiferromagnetic (AFM) were computed for both P4mm and P4/mmm structures. The total energy results reveal that the FM non-centrosymmetric structure is found to be the most stable magnetic ground state. The electronic band structure, density of states (DOS) and the electron localization function (ELF) were calculated for the stable FM structure. ELF revealed the distorted non-centrosymmetric structure. The band structure and DOS for the majority spins of FM PbMnO3showed no band gap at the Fermi level. However, a gap opens up at the Fermi level in minority spin channel suggesting that it could be a half-metal and a potential spintronic candidate.

PHOTOEMISSION STUDY OF PURE AND Cs-INTERCALATED VSe2

1994 ◽  
Vol 08 (20) ◽  
pp. 1261-1268 ◽  
Author(s):  
H.I. STARNBERG ◽  
H.E. BRAUER ◽  
P.O. NILSSON ◽  
L.J. HOLLEBOOM ◽  
H.P. HUGHES
Keyword(s):  
Charge Transfer ◽  
Band Structure ◽  
Valence Band ◽  
Band Model ◽  
Valence Band Structure ◽  
Band Structure Calculations ◽  
Band Dispersion ◽  
Self Consistent ◽  
Photoemission Study ◽  
Structure Calculations

We report photoemission studies of the valence band structure of VSe 2 and of VSe2 intercalated with Cs. Pure VSe 2 showed significant band dispersion both perpendicular and parallel to the layers, i.e. the valence band of VSe 2 is 3D in character, confirming self-consistent LAPW band structure calculations. After Cs intercalation the perpendicular band dispersion vanished, while that parallel to the layers remained, showing that the valence band structure had become 2D. The observed changes go far beyond the rigid band model, but are largely understandable in terms of intercalation-induced decoupling of the VSe 2 layers, and charge transfer from the Cs.

Message Passing Neural Networks for Partial Charge Assignment to Metal-Organic Frameworks

2020 ◽  
Author(s):  
Ali Raza ◽  
Arni Sturluson ◽  
Cory Simon ◽  
Xiaoli Fern
Keyword(s):  
Electronic Structure ◽  
Message Passing ◽  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Computational Cost ◽  
Electronic Structure Calculations ◽  
High Fidelity ◽  
Partial Charges ◽  
Metal Organic ◽  
Structure Calculations

Virtual screenings can accelerate and reduce the cost of discovering metal-organic frameworks (MOFs) for their applications in gas storage, separation, and sensing. In molecular simulations of gas adsorption/diffusion in MOFs, the adsorbate-MOF electrostatic interaction is typically modeled by placing partial point charges on the atoms of the MOF. For the virtual screening of large libraries of MOFs, it is critical to develop computationally inexpensive methods to assign atomic partial charges to MOFs that accurately reproduce the electrostatic potential in their pores. Herein, we design and train a message passing neural network (MPNN) to predict the atomic partial charges on MOFs under a charge neutral constraint. A set of ca. 2,250 MOFs labeled with high-fidelity partial charges, derived from periodic electronic structure calculations, serves as training examples. In an end-to-end manner, from charge-labeled crystal graphs representing MOFs, our MPNN machine-learns features of the local bonding environments of the atoms and learns to predict partial atomic charges from these features. Our trained MPNN assigns high-fidelity partial point charges to MOFs with orders of magnitude lower computational cost than electronic structure calculations. To enhance the accuracy of virtual screenings of large libraries of MOFs for their adsorption-based applications, we make our trained MPNN model and MPNN-charge-assigned computation-ready, experimental MOF structures publicly available.<br>

scholarly journals Quantum HF/DFT-embedding algorithms for electronic structure calculations: Scaling up to complex molecular systems

2021 ◽  
Vol 154 (11) ◽  
pp. 114105
Author(s):  
Max Rossmannek ◽  
Panagiotis Kl. Barkoutsos ◽  
Pauline J. Ollitrault ◽  
Ivano Tavernelli
Keyword(s):  
Electronic Structure ◽  
Electronic Structure Calculations ◽  
Scaling Up ◽  
Molecular Systems ◽  
Structure Calculations
Sign in / Sign up

Export Citation Format

Share Document