Search results for "Supercell"

showing 3 items of 23 documents

Mesoscopic Scale Structural Instability in Ferroelectrics

2009

First-principles statistics addressed to structural phase transitions and temperature development of ferroelectric response is derived within the framework of the Fokker-Planck (Smoluchowsky) equation as complementary to the Monte Carlo [R.D King-Smith., D Vanderbilt, Phys. Rev. B 49, 5828–5844 (1994)] and molecular dynamics [T. Nishimatsu, U. V Waghmare, Y. Kawazoe., D. Vanderbilt, arXiv:0804.1853v2] simulations. Illustrative example of is given for 5 × 5 × 5 BaTiO 3 supercell.

PhysicsMesoscopic physicsCondensed matter physicsScale (ratio)Monte Carlo methodCondensed Matter PhysicsInstabilityFerroelectricityElectronic Optical and Magnetic MaterialsCondensed Matter::Materials ScienceMolecular dynamicsQuantum mechanicsSupercell (crystal)Fokker–Planck equationFerroelectrics
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Quantum-chemical simulations of free and bound hole polarons in corundum crystal

1997

Abstract The semi-empirical method of the so-called intermediate neglect of differential overlap (INDO) has been applied to the calculations of the hole small-radius polarons in corundum crystals. Results for optimized atomic and electronic structure using two different approaches (the molecular cluster and periodic, supercell model) are critically compared. It is shown that the main results are similar in both cases.

Quantum chemicalGeneral Computer ScienceChemistryExcitonGeneral Physics and AstronomyCorundumGeneral ChemistryElectronic structureengineering.materialPolaronCrystalComputational MathematicsMechanics of MaterialsengineeringSupercell (crystal)General Materials ScienceAtomic physicsParametrizationComputational Materials Science
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Vacancy Defects in Ga2O3: First-Principles Calculations of Electronic Structure

2021

This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP08856540) as well as by the Latvian research council via the Latvian National Research Program under the topic ?High-Energy Physics and Accelerator Technologies?, Agreement No: VPP-IZM-CERN-2020/1-0002 for A.I. Popov. In addition, J. Purans is grateful to the ERAF project 1.1.1.1/20/A/057 while A. Platonenko was supported by Latvian Research Council No. LZP-2018/1-0214. The authors thank A. Lushchik and M. Lushchik for many useful discussions. The research was (partly) performed in the Institute of Solid State Physics, University of Latvia ISSP UL. ISSP UL as…

TechnologyDEEP DONOR02 engineering and technologyConductivityDFT01 natural sciencesOXYGENCrystalpoint defectsGeneral Materials ScienceDENSITY FUNCTIONAL THEORYGalliump-type conductivityMicroscopyQC120-168.85Condensed matter physicsMONOCLINICSTP TYPE CONDUCTIVITYELECTRONIC.STRUCTUREEngineering (General). Civil engineering (General)021001 nanoscience & nanotechnology3. Good healthCALCULATIONSβ-Ga<sub>2</sub>O<sub>3</sub>OXYGEN VACANCIES:NATURAL SCIENCES [Research Subject Categories]Density functional theoryElectrical engineering. Electronics. Nuclear engineeringTA1-20400210 nano-technologyPOINT DEFECTSFIRST PRINCIPLE CALCULATIONSβ-Ga2O3Materials scienceP-TYPE CONDUCTIVITYELECTRONIC STRUCTUREVACANCY DEFECTSchemistry.chemical_elementElectronic structureFIRST-PRINCIPLE DENSITY-FUNCTIONAL THEORIESGALLIUM COMPOUNDSArticleDENSITY-FUNCTIONAL-THEORYVacancy defect0103 physical sciences010306 general physicsΒ-GA2 O3QH201-278.5HYBRID EXCHANGEoxygen vacancyCrystallographic defectTK1-9971Descriptive and experimental mechanicschemistryGALLIUMdeep donorSupercell (crystal)DFT; β-Ga<sub>2</sub>O<sub>3</sub>; oxygen vacancy; deep donor; p-type conductivity; point defectsOXYGEN VACANCYMaterials
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