Interaction between copper(II) ions through the azido bridge: concept of spin polarization and ab initio calculations on model systems

1986 ◽  
Vol 108 (10) ◽  
pp. 2574-2581 ◽  
Author(s):  
Marie France. Charlot ◽  
Olivier. Kahn ◽  
Max. Chaillet ◽  
Christiane. Larrieu
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Spin Polarization ◽  
Model Systems

Electronic Structure of Defects in Fcc-C22

2006 ◽  
Vol 965 ◽  
Author(s):  
Helder Sousa Domingos
Keyword(s):  
Electronic Structure ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Spin Polarization ◽  
Dopant Concentration ◽  
Magnetic Polarization ◽  
Carbon Allotrope

ABSTRACTClassical and ab-initio calculations were carried out on bulk defects and surfaces of the carbon allotrope Fcc-C22. The results revealed a number of possible defects with spin polarization and one with antiferromagnetic character. The surfaces were shown to be able to host magnetic polarization. Extrinsic light dopants (H and N) were shown to introduce spin polarization for small dopant concentration and to metallize the systems for large concentrations.

Ab initio calculations of spin polarization at Co2CrAl/GaAs interfaces

2004 ◽  
Vol 16 (48) ◽  
pp. S5725-S5728 ◽  
Author(s):  
Kazutaka Nagao ◽  
Masafumi Shirai ◽  
Yoshio Miura
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Spin Polarization

scholarly journals A lattice-dynamical refinement approach based on periodic ab-initio calculations

2014 ◽  
Vol 70 (a1) ◽  
pp. C1441-C1441
Author(s):  
Anders Madsen
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electron Density ◽  
High Performance ◽  
Normal Modes ◽  
Thermal Motion ◽  
Model Systems ◽  
Model Parameters ◽  
Large Area ◽  
X Ray

The use of synchrotron radiation and large area detectors has increased the quality and quantity of X-ray and neutron diffraction data within the last decades. These advances call for new and better approaches to model and to interpret the data. Elastic X-ray diffraction corresponds to the Fourier transform of the thermally averaged electron density in the unit cell. This density is normally approximated as the convolution of a sum of static atomic densities and the thermal motion of the individual atoms. The static densities and thermal motion are equally important: Together they conform the entire model refined against a single set of measured data, and they must both be modeled correctly, or neither is. The advent of high-performance computers has made it feasible to obtain lattice-dynamical models based on periodic quantum-mechanical calculations, to describe the concerted motion of atoms and molecules through the crystal. Our recent calculations of Debye-Waller factors based on periodic ab-initio calculations for various molecular test systems [1] has prepared the ground for proposing the refinement of quantum-mechanically derived normal modes of vibration against diffraction experiments. As opposed to the standard approach using independent atomic motion, some of the advantages and possibilities that emerge are: 1. A physically reasonable picture of the molecular motion in the crystal. 2. Refinement against data obtained at multiple temperatures in a common model. 3. Modeling thermal diffuse scattering. 4. Reduction of the number of model parameters. 5. Anisotropic motion of H atoms. The approach is computationally expensive, but may prove useful for electron density studies, studies of thermal effects in crystals, i.e. studies of thermochromic and thermoelectric compounds, solid-state phase-transitions and to derive thermodynamic properties, e.g. free energies of polymorphic crystals. We will introduce the method and present some first results for model systems.

scholarly journals Bonding in 1,2,3-Triazoles. VII. Effects of N-Substitution. Ab Initio Calculations on Model Systems.

1993 ◽  
Vol 47 ◽  
pp. 943-949 ◽  
Author(s):  
Kurt Nielsen ◽  
Inger Søtofte ◽  
Helge Johansen ◽  
Erwan Le Clouerec ◽  
Jaume Casabó ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Model Systems
Sign in / Sign up

Export Citation Format

Share Document