Electronic States of Fe2S-/0/+

2003 ◽  
Vol 68 (2) ◽  
pp. 405-422 ◽  
Author(s):  
Olaf Hübner ◽  
Joachim Sauer
Keyword(s):  
Density Functional ◽  
Theoretical Calculations ◽  
Electronic States ◽  
Spin Coupling ◽  
Heisenberg Spin ◽  
Complete Active Space ◽  
Dynamic Correlation ◽  
High Spin States ◽  
Consistent Field ◽  
Self Consistent Field

The relative energies of a multitude of low-lying electronic states of Fe2S-/0/+ are determined by complete active space self-consistent field (CASSCF) calculations. The numerous states obtained are assigned to spin ladders. For selected states, dynamic correlation has been included by multireference configuration interaction (MRCI) and the structures of some high-spin states have been optimized by CASSCF/MRCI. Comparison is made with structures obtained by density-functional theoretical calculations. The ground states of Fe2S-/0/+ are 10B2, 1A1 and 8A2, respectively, and the total splittings of the lowest-energy spin ladders are about 0.18, 0.07 and 0.13 eV, respectively. The spin ladders of Fe2S qualitatively reflect the picture of Heisenberg spin coupling. While both Fe2S- and Fe2S+ show an Fe-Fe distance of about 270 pm, that of Fe2S is about 100 pm longer. The calculated adiabatic electron affinity of Fe2S is 1.2 eV and the ionization energy 6.6 eV. An interpretation of the observed photoelectron spectrum of Fe2S- is given.

scholarly journals Redox-Active Dysprosium Single-Molecule Magnet: Spectro-Electrochemistry and Theoretical Investigations

2019 ◽  
Vol 5 (3) ◽  
pp. 46 ◽  
Author(s):  
Guglielmo Fernandez Garcia ◽  
Vincent Montigaud ◽  
Lucie Norel ◽  
Olivier Cador ◽  
Boris Le Guennic ◽  
...  
Keyword(s):  
Single Molecule ◽  
Density Functional ◽  
Functional Theory ◽  
Single Molecule Magnet ◽  
Complete Active Space ◽  
Consistent Field ◽  
Redox Active ◽  
Theoretical Investigations ◽  
Td Dft ◽  
Self Consistent Field

The mononuclear single-molecule magnet (SMM) [Dy(tta)3(L)]⋅C6H14 (1) (where tta− = 2-thenoyltrifluoroacetonate and L = 4,5-bis(propylthio)-tetrathiafulvalene-2-(2-pyridyl)benzimidazole-methyl-2-pyridine) was studied by spectro-electrochemistry. The resulting electronic spectra of the three oxidation states 1, 1+∙, and 12+ were rationalized by time-dependent density functional theory (TD-DFT) calculations starting from the DFT optimized structures. The modulation of the magnetic anisotropy of the DyIII center upon oxidation was also inspected at the Complete Active Space Self-Consistent Field (CASSCF) level of calculation.

Complete active space self‐consistent field and density functional study of FNO

1994 ◽  
Vol 100 (1) ◽  
pp. 459-463 ◽  
Author(s):  
Theodore S. Dibble ◽  
Joseph S. Francisco ◽  
Robert J. Deeth ◽  
Michael R. Hand ◽  
Ian H. Williams
Keyword(s):  
Density Functional ◽  
Functional Study ◽  
Density Functional Study ◽  
Complete Active Space ◽  
Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

scholarly journals A multiconfigurational approach to the electronic structure of trichromium extended metal atom chains

2017 ◽  
Vol 46 (19) ◽  
pp. 6202-6211 ◽  
Author(s):  
M. Spivak ◽  
V. Arcisauskaite ◽  
X. López ◽  
J. E. McGrady ◽  
C. de Graaf
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Metal Atom ◽  
Density Functional ◽  
Functional Theory ◽  
Complete Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Capping Ligands

Density functional theory, Complete Active Space Self-Consistent Field (CASSCF) and perturbation theory (CASPT2) methodologies have been used to explore the electronic structure of a series of trichromium Extended Metal Atom Chains (EMACS) with different capping ligands.

Theoretical electronic investigation of the low-lying electronic states of the LuF molecule

2009 ◽  
Vol 87 (11) ◽  
pp. 1163-1169 ◽  
Author(s):  
Y. Hamade ◽  
F. Taher ◽  
M. Choueib ◽  
Y. Monteil
Keyword(s):  
Ground State ◽  
Electronic States ◽  
Electronic Energy ◽  
Wave Number ◽  
Spectroscopic Constants ◽  
Complete Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Calculated Potential Energy

The theoretical electronic structure of the LuF molecule is investigated, using the Complete Active-Space Self-Consistent Field CASSCF and the MultiReference Configuration Interaction MRCI methods. These methods are performed for 26 electronic states in the representation 2s+1Λ(+/−), neglecting spin–orbit effects. Spectroscopic constants including the harmonic vibrational wave number ωe (cm–1), the relative electronic energy Te (cm–1) referred to the ground state and the equilibrium internuclear distance Re (Å) are predicted for all the singlet and triplet electronic states situated below 50 000 cm–1. Calculated potential energy curves are also reported.

Theoretical calculation of the low-lying doublet electronic states of the SrF molecule

2014 ◽  
Vol 92 (10) ◽  
pp. 1223-1231 ◽  
Author(s):  
F. Jardali ◽  
M. Korek ◽  
G. Younes
Keyword(s):  
Electronic States ◽  
Electronic Energy ◽  
Harmonic Frequency ◽  
Complete Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Schrödinger Perturbation ◽  
First Time ◽  
Good Agreement

The potential energy curves of the low-lying doublet electronic states in the representation 2s+1Λ(+/−) of the SrF molecule have been investigated by using the complete active space self-consistent field with multireference configuration interaction and multireference Rayleigh–Schrödinger perturbation theory methods. The harmonic frequency, ωe; the internuclear distance, Re; the dipole moment; and the electronic energy with respect to the ground state, Te, have been calculated for the considered electronic states. The eigenvalues, Ev; the rotational constants, Bv; and the abscissas of the turning points, Rmin and Rmax, have been investigated using the canonical functions approach. The comparison between the values of the present work and those available in the literature for several electronic states shows very good agreement. Nine new electronic states have been investigated here for the first time.

GEOMETRIES AND ENERGY SEPARATIONS OF ELECTRONIC STATES OF In3N, InN3, AND THEIR IONS

2008 ◽  
Vol 07 (04) ◽  
pp. 751-765 ◽  
Author(s):  
ZHIJI CAO ◽  
KRISHNAN BALASUBRAMANIAN
Keyword(s):  
Ground State ◽  
Electronic States ◽  
Closed Shell ◽  
Spectroscopic Properties ◽  
Electron Affinities ◽  
Complete Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Equilibrium Geometries

Spectroscopic properties of the low-lying electronic states of In 3 N , InN 3, and their ions are computed by the complete active-space self-consistent field (CASSCF) followed by multireference singles + doubles configuration interaction (MRSDCI) calculations. Our results predict that the spectra of In 3 N / InN 3 are substantially different from those of Ga 3 As / GaAs 3 and Al 3 P / AlP 3 tetramers. The ground state of In 3 N is a closed-shell 1 A ′1 state with a planar D 3h symmetry, whereas the ground state of InN 3 is a 1Σ+ state of linear In – N – N – N structure. The equilibrium geometries, vibrational frequencies, atomization energies, adiabatic ionization potentials, electron affinities, and other properties are discussed.

scholarly journals Electronic Structure of Cubane-Like Vanadium–Nitrogen Cationic Clusters [V4N4]+ and [V6N6]+

Inorganics ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 52
Author(s):  
He ◽  
Zhang ◽  
McGrady
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Mass Spectrometric ◽  
Bond Orders ◽  
Functional Theory ◽  
Complete Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field

Density Functional Theory and Complete Active Space Self-Consistent Field (CASSCF) methodologies are used to explore the electronic structure of the cationic V–N clusters, [V4N4]+ and [V6N6]+, that have been identified in recent mass spectrometric experiments. Our calculations indicate that both clusters are based on cubane-like fragments of the rock-salt lattice. In the smaller [V4N4]+ cluster, the V–V bonding is delocalized over the tetrahedron, with net bond orders of 1/3 per V–V bond. In [V6N6]+, in contrast, the V–V bonding is strongly localized in the central V2N2 unit, which has a short V=V double bond. CASSCF calculations reveal that both localized and delocalized V–V bonds are highly multi-configurational.

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