Search results for "Ab-initio calculations"

showing 3 items of 3 documents

Lower mantle hydrogen partitioning between periclase and perovskite : a quantum chemical modelling

2016

Abstract Partitioning of hydrogen (often referred to as H2O) between periclase (pe) and perovskite (pvk) at lower mantle conditions (24–80 GPa) was investigated using quantum mechanics, equilibrium reaction thermodynamics and by monitoring two H-incorporation models. One of these (MSWV) was based on replacements provided by Mg2+ ↔ 2H+ and Si4+ ↔ 4H+; while the other (MSWA) relied upon substitutions in 2Mg2+ ↔ Al3+ + H+ and Si4+ ↔ Al3+ + H+. H2O partitioning in these phases was considered in the light of homogeneous (Bulk Silicate Earth; pvk: 75%–pe:16% model contents) and heterogeneous (Layered Mantle; pvk:78%–pe:14% modal contents) mantle geochemical models, which were configured for lower…

010504 meteorology & atmospheric sciencesHydrogenpericlaseAnalytical chemistrySocio-culturalechemistry.chemical_elementengineering.material010502 geochemistry & geophysics01 natural sciencesMantle (geology)chemistry.chemical_compoundGeochemistry and PetrologyOrganic chemistryH2O-partitioningperovskiteEquilibrium constant0105 earth and related environmental sciencesChemistryAb-initio calculationslowermantle; H2O-partitioning; periclase; perovskite.SilicatePartition coefficientlower mantleAnhydrousengineeringPericlaseChemical equilibriumlower mantle H2O-partitioning Ab-initio calculations periclase perovskite
researchProduct

Magnetic field-induced alignment of molecular rotor-shaped cyclophanes

2010

Molecular pinwheels consisting of dipolar substituted cyclophanes in solution can function as free microscopic rotors in the presence of a homogeneous static magnetic field B and a circularly polarized electric field E rotating on a plane containing B. Owing to the high magnetic anisotropy of [26](1,2,3,4,5,6)cyclophane and [36](1,2,3,4,5,6)cyclophane biased by strong ring currents, ∼1 in 105 molecules are expected to align with the C6 symmetry axis perpendicular to a magnetic field of 21 T. The magnetic-field-controlled alignment of rotor-shaped cyclophanes is insignificantly affected by nonpolar solvents, for example, toluene.

ChemistryRotor-shaped cyclophanes; molecular engines; magnetic field-controlled molecular alignment; dipolar rotors in circularly polarized electric field; ab-initio calculations; solvent effectsMagnetostaticsMolecular physicsSymmetry (physics)Magnetic fieldDipolechemistry.chemical_compoundMagnetic anisotropyNuclear magnetic resonanceElectric fieldPerpendicularGeneral Materials SciencePhysical and Theoretical ChemistryCyclophane
researchProduct

Ab-Initio Calculations of Oxygen Vacancy in Ga2O3 Crystals

2021

The research has been funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (Grant No. AP08856540). J. Purans and A.I.Popov acknowledge the ERAF project 1.1.1.1/20/A/057 “Functional Ultrawide Bandgap Gallium Oxide and Zinc Gallate Thin Films and Novel Deposition Technologies”. The Institute of Solid State Physics, University of Latvia (Latvia) as the Centre of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD01-2016-2017-Teaming Phase2 under grant agreement No. 739508, project CAMART2.

ab-initio calculationsβ-ga2o3band structureQC1-999β-GaOGeneral Physics and Astronomy02 engineering and technologyDFT01 natural sciences7. Clean energyZinc gallateGallium oxideAb initio quantum chemistry methodsPolitical science0103 physical sciences:NATURAL SCIENCES:Physics [Research Subject Categories]media_common.cataloged_instanceEuropean unionmedia_common010302 applied physicsPhysicsGeneral Engineeringoxygen vacancydft021001 nanoscience & nanotechnologyEngineering physicsOxygen vacancy3. Good healthChristian ministry0210 nano-technologyLatvian Journal of Physics and Technical Sciences
researchProduct