Z.D.O. Hartree-Fock calculation of the spin density distributions in some aza-hydrocarbon radical ions

1966 ◽  
Vol 62 ◽  
pp. 3273 ◽  
Author(s):  
M. A. Ali ◽  
A. Hinchliffe
Keyword(s):  
Spin Density ◽  
Hydrocarbon Radical ◽  
Radical Ions ◽  
Hartree Fock ◽  
Density Distributions

Spin density and bonding in the CoCI 2– 4 ion in Cs 3 CoCl 5 - III. The comparison of theory and experiment

1982 ◽  
Vol 384 (1786) ◽  
pp. 31-48 ◽  
Keyword(s):  
Spin Density ◽  
Cobalt Atom ◽  
Theoretical Data ◽  
Total Spin ◽  
Cubic Symmetry ◽  
Hartree Fock ◽  
Density Distributions ◽  
Tetragonal Crystal ◽  
Structure Factors ◽  
Experimental Parameters

We report improvement in the precision of certain of the polarized neutron diffraction data for Cs 3 CoCl 5 . The improvement allows us to analyse the data using a chemically based model of the spin-density distribution that is equivalent to a conventional multipole treatment to fourth order on the cobalt, and to second order on the chlorine atoms of the CoCl 2– 4 ion. To test the completeness of the model and to understand the meaning of the parameters in terms of the wavefunction, we have used it to analyse a set of theoretical magnetic structure factors. These are obtained from the wave-function of a Hartree–Fock calculation on the CoCl 2– 4 ion. We obtain an excellent fit to the theoretical ‘data’ and a much improved fit to the experimental data when the new model is used. We confirm the main features of the spin- and charge-density distributions deduced in our previous study, and we are now also able to interpret the experimental parameters in terms of the wavefunction by analogy with the fit to the theoretical data. We find that there is ca . 3 % of the total spin delocalized onto each chlorine atom of the CoCl 2– 4 ion, dominantly via σ - rather than π -bonding. There is a well defined diffuse spin density on the cobalt atom of 4p symmetry, and strong evidence for 3d–4p mixing. The spin density, in this almost cubic ion, has distinct non-cubic symmetry, which may arise from longer-range effects due to the rest of the tetragonal crystal.

Unrestricted Hartree-Fock spin density distributions in nitro aromatic radical anions

1971 ◽  
Vol 22 (4) ◽  
pp. 369-377 ◽  
Author(s):  
D. N. Nanda ◽  
J. Subramanian ◽  
P. T. Narasimhan
Keyword(s):  
Spin Density ◽  
Radical Anions ◽  
Aromatic Radical ◽  
Hartree Fock ◽  
Density Distributions ◽  
Nitro Aromatic

Computational Investigation of the Asymmetry in Photosynthetic Reaction Center Models from First Principles

2020 ◽  
Author(s):  
Denis Artiukhin ◽  
Patrick Eschenbach ◽  
Johannes Neugebauer
Keyword(s):  
Spin Density ◽  
Reaction Center ◽  
Density Functional ◽  
Photosynthetic Reaction Center ◽  
Chem Phys ◽  
Molecular Structures ◽  
Error Characteristic ◽  
Molecular Systems ◽  
Density Distributions ◽  
The Asymmetry

We present a computational analysis of the asymmetry in reaction center models of photosystem I, photosystem II, and bacteria from <i>Synechococcus elongatus</i>, <i>Thermococcus vulcanus</i>, and <i>Rhodobacter sphaeroides</i>, respectively. The recently developed FDE-diab methodology [J. Chem. Phys., 148 (2018), 214104] allowed us to effectively avoid the spin-density overdelocalization error characteristic for standard Kohn–Sham Density Functional Theory and to reliably calculate spin-density distributions and electronic couplings for a number of molecular systems ranging from dimeric models in vacuum to large protein including up to about 2000 atoms. The calculated spin densities showed a good agreement with available experimental results and were used to validate reaction center models reported in the literature. We demonstrated that the applied theoretical approach is very sensitive to changes in molecular structures and relative orientation of molecules. This makes FDE-diab a valuable tool for electronic structure calculations of large photosynthetic models effectively complementing the existing experimental techniques.

THE INNER CRUST OF NEUTRON STARS IN RELATIVISTIC MEAN FIELD APPROACH

2008 ◽  
Vol 17 (09) ◽  
pp. 1765-1773 ◽  
Author(s):  
JIGUANG CAO ◽  
ZHONGYU MA ◽  
NGUYEN VAN GIAI
Keyword(s):  
Boundary Conditions ◽  
Neutron Stars ◽  
Mean Field ◽  
Bcs Theory ◽  
Neutron Density ◽  
Field Approach ◽  
Hartree Fock ◽  
Relativistic Mean Field ◽  
Density Distributions ◽  
Rmf Model

The microscopic properties and superfluidity of the inner crust in neutron stars are investigated in the framework of the relativistic mean field(RMF) model and BCS theory. The Wigner-Seitz(W-S) cell of inner crust is composed of neutron-rich nuclei immersed in a sea of dilute, homogeneous neutron gas. The pairing properties of nucleons in the W-S cells are treated in BCS theory with Gogny interaction. In this work, we emphasize on the choice of the boundary conditions in the RMF approach and superfluidity of the inner crust. Three kinds of boundary conditions are suggested. The properties of the W-S cells with the three kinds of boundary conditions are investigated. The neutron density distributions in the RMF and Hartree-Fock-Bogoliubov(HFB) models are compared.

Microscopic description of the fusion excitation function of 32,36S+90,94,96Zr

2020 ◽  
Vol 29 (07) ◽  
pp. 2050046
Author(s):  
M. Rashdan ◽  
T. A. Abdel-Karim
Keyword(s):  
Excitation Function ◽  
Excited States ◽  
Density Functional ◽  
Neutron Density ◽  
Energy Density Functional ◽  
Hartree Fock ◽  
Density Distributions ◽  
Text Interaction ◽  
Good Agreement

The fusion excitation function for the systems [Formula: see text]S+[Formula: see text]Zr is investigated using a microscopic internuclear potential derived from Skyrme energy density functional. The inputs in this approach are the proton and neutron density distributions of the interacting nuclei, which are derived from Skyrme–Hartree–Fock calculations. The SkM[Formula: see text] interaction is used in the calculation of the nuclear densities as well as the internuclear potential. The coupling to low lying inelastic excited states of target and projectile is considered. The role of the neutron transfer is discussed, where it is considered through the CCFULL model calculation. A good agreement with the experimental data is obtained without adjustable parameters.

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