Calculation of spin densities of radicals of pyrimidine-type bases by density functional theory. Influence of solvent and comparison with EPR results

2000 ◽  
Vol 2 (18) ◽  
pp. 4207-4211 ◽  
Author(s):  
S. Naumov ◽  
A. Barthel ◽  
J. Reinhold ◽  
F. Dietz ◽  
J. Geimer ◽  
...  
2020 ◽  
Vol 224 ◽  
pp. 201-226
Author(s):  
Anja Massolle ◽  
Johannes Neugebauer

Subsystem DFT allows easy access to spin densities for arbitrary broken-symmetry states of radical aggregates.


2006 ◽  
Vol 15 (02) ◽  
pp. 553-559
Author(s):  
JOHANN BARTEL ◽  
KAMEL BENCHEIKH ◽  
PHILIPPE QUENTIN

The structure of spin densities and the associated spin-current densities, induced by the coupling of external vector fields to the orbital and spin degrees of freedom, is studied within the framework of the Extended Thomas-Fermi method, a semiclassical version of the density-functional theory. A special emphasis is put on the rotational case where our approach amounts to perform a semiclassical approximation of the so-called generalized Routhian approach.


1994 ◽  
Vol 72 (3) ◽  
pp. 695-704 ◽  
Author(s):  
Maggie A. Austen ◽  
Leif A. Eriksson ◽  
Russell J. Boyd

The linear combination of Gaussian-type orbitals–density functional theory (LCGTO–DFT) approach is used to study geometries and hyperfine structures of a set of neutral radicals. Each of the title molecules is investigated by means of local density approximation calculations, and using the Becke–Perdew and Perdew–Wang–Perdew corrections to the exchange and correlation functionals. The effects of local vs. non-local potentials and of various basis sets are investigated. Total densities and unpaired spin densities are compared. The isotropic couplings are found to be very dependent on the type of exchange functional used, whereas the anisotropic couplings are relatively insensitive to the choice of basis set and functional. In most cases, the Perdew–Wang exchange corrections provide isotropic couplings in satisfactory agreement with experiment.


Molecules ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 187
Author(s):  
Piotr Niemiec ◽  
Renata Tokarz-Sobieraj ◽  
Małgorzata Witko

Density functional theory calculations were carried out to investigate the electronic structures of Keggin-typed [XMo12O40]n− and [XW12O40]n− anions with different heteroatoms (X = Zn2+, B3+, Al3+, Ga3+, Si4+, Ge4+, P5+, As5+, and S6+). The influence of solvent on redox properties of heteropolyanions was discussed. For [XW12O40]n− systems two linear correlation: first, between the experimental redox potential and energies of LUMO orbital; and second, between the experimental redox potential and total energy interaction (calculated between internal tetrahedron (XO4n−), and rest of Kegging anion skeleton, (W12O36)) were designated. Taking into account the similarity of XW12O40n− and XMo12O40n− systems (in geometry and electronic structure), the estimated redox potential of molybdenum heteropolyanions (with X being p block elements) in different solvent were proposed.


2021 ◽  
Vol 72 (1) ◽  
pp. 541-564
Author(s):  
Prachi Sharma ◽  
Jie J. Bao ◽  
Donald G. Truhlar ◽  
Laura Gagliardi

Kohn-Sham density functional theory with the available exchange–correlation functionals is less accurate for strongly correlated systems, which require a multiconfigurational description as a zero-order function, than for weakly correlated systems, and available functionals of the spin densities do not accurately predict energies for many strongly correlated systems when one uses multiconfigurational wave functions with spin symmetry. Furthermore, adding a correlation functional to a multiconfigurational reference energy can lead to double counting of electron correlation. Multiconfiguration pair-density functional theory (MC-PDFT) overcomes both obstacles, the second by calculating the quantum mechanical part of the electronic energy entirely by a functional, and the first by using a functional of the total density and the on-top pair density rather than the spin densities. This allows one to calculate the energy of strongly correlated systems efficiently with a pair-density functional and a suitable multiconfigurational reference function. This article reviews MC-PDFT and related background information.


2009 ◽  
Vol 87 (10) ◽  
pp. 1451-1459 ◽  
Author(s):  
A. B.P. Lever

Density functional theory and the polarized continuum model are used to derive the electronic structures of some open-shell, bis(bipyridine)ruthenium complexes bound to noninnocent quinonoid or thiolosulfinato ligands formally in the semiquinone oxidation state. The noninnocent properties of the o-thiolosulfinato ligand are explored and compared with those of the more conventional o-semiquinones with nitrogen, oxygen, and sulfur donor atoms. Spin densities are shown to be fairly localized in the metallocycle ring. It is demonstrated that oxidation of the parent [RuII(bpy)2 (1,2-(S,SO2)–C6H4] species occurs primarily in the metallocycle ring and is localized in the Ru–S0 bond.


Sign in / Sign up

Export Citation Format

Share Document