A Modern First-Principles View on Ligand Field Theory Through the Eyes of Correlated Multireference Wavefunctions

Atanasov, Mihail; Ganyushin, Dmitry; Sivalingam, Kantharuban; Neese, Frank

doi:10.1007/430_2011_57

Cited by 154 publications

(190 citation statements)

References 172 publications

Supporting

Mentioning

185

Contrasting

Order By: Relevance

“…Thus, it is reasonable to consider the d-orbital splitting as the starting point for the discussion. Figure 1 shows the energy splitting of all of the studied geometries based on ab initio ligand field theory (AILFT) [19] energies for the d-orbitals (see Materials and Methods section for further information). Figure 2 presents molecular geometries for model complexes.…”

Section: D-orbital Splittingmentioning

confidence: 99%

“…Converged CASSCF wave functions served as a basis to build the state interaction matrix of the spin-orbit coupling (SOC) operator (quasi degenerate perturbation theory (QDPT) approach). Zero-field splitting parameters (D and E) obtained by second-order perturbation theory and effective Hamiltonian approaches were compared, and d-orbital splitting was analyzed in terms of ab initio ligand field theory (AILFT) [19]. In all cases, CASSCF and NEVPT2 ground states corresponded to the highest multiplicity computed (quintet for Fe(II) and quartet for Co(II)).…”

Section: Computational Detailsmentioning

confidence: 99%

“…Nowadays, CASSCF calculations are widely applied for the rationalization of magnetic properties of mononuclear single molecule magnets based on transition metal ions and lanthanides [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Besides energies and wave functions, ab initio calculations can be analyzed in terms of Spin-Hamiltonian and ligand field parameters [19][20][21]. In this way, experimentally derived parameters as zero-field splitting D and E, effective g-factors, and Racah and ligand field parameters can be directly compared with their calculated counterparts.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effect of Low Spin Excited States for Magnetic Anisotropy of Transition Metal Mononuclear Single Molecule Magnets

Llanos

Aravena

2018

Inorganics

View full text Add to dashboard Cite

Rational, fine tuning of magnetic anisotropy is critical to obtain new coordination compounds with enhanced single molecule magnet properties. For mononuclear transition metal complexes, the largest contribution to zero-field splitting is usually related to the excited states of the same spin as the ground level. Thus, the contribution of lower multiplicity roots tends to be overlooked due to its lower magnitude. In this article, we explore the role of lower multiplicity excited states in zero-field splitting parameters in model structures of Fe(II) and Co(II). Model aquo complexes with coordination numbers ranging from 2 to 6 were constructed. The magnetic anisotropy was calculated by state of the art ab initio methodologies, including spin-orbit coupling effects. For non-degenerate ground states, contributions to the zero-field splitting parameter (D) from highest and lower multiplicity roots were of the same sign. In addition, their relative magnitude was in a relatively narrow range, irrespective of the coordination geometry. For degenerate ground states, the contribution from lower multiplicity roots was significantly smaller. Results are rationalized in terms of general expressions for D and are expected to be reasonably transferable to real molecular systems.

show abstract

Section: D-orbital Splittingmentioning

confidence: 99%

Section: Computational Detailsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Low Spin Excited States for Magnetic Anisotropy of Transition Metal Mononuclear Single Molecule Magnets

Llanos

Aravena

2018

Inorganics

View full text Add to dashboard Cite

show abstract

“…Furthermore, the keyword dorbs automatically triggers the ab initio ligand field analysis (AILFT). [348] The approach has been reported in a number of applications. [349,350] For more details on the AILFT approach, we refer to the respective manual section and the CASSCF tutorial, where examples are shown.…”

Section: Final Orbitals Optionsmentioning

confidence: 99%

Units and Conversion Factors

2010

Working Guide to Pumps and Pumping Stations

View full text Add to dashboard Cite

“…At the very beginning ligand field theory was operated with only empirical parameters [6,7]. However in the last few decades, the ligand field concept was often used in conjunction with first principles modeling studies either at the wavefunction [8][9][10] or density functional levels of theory [11][12][13][14][15]. The important growth of computational technics also has a non-negligible impact on the development of non-empirical ligand field calculation.…”

Section: Introductionmentioning

confidence: 99%

Electronic fine structure calculation of metal complexes with three-open-shell s, d, and p configurations

Ramanantoanina

Daul

2017

J Mol Model

View full text Add to dashboard Cite

The ligand field density functional theory (LFDFT) algorithm is extended to treat the electronic structure and properties of systems with three-open-shell electron configurations, exemplified in this work by the calculation of the core and semi-core 1s, 2s, and 3s one-electron excitations in compounds containing transition metal ions. The work presents a model to non-empirically resolve the multiplet energy levels arising from the three-open-shell systems of non-equivalent ns, 3d, and 4p electrons and to calculate the oscillator strengths corresponding to the electric-dipole 3d m → ns 1 3d-m 4p 1 transitions, with n = 1, 2, 3 and m = 0, 1, 2, …, 10 involved in the s electron excitation process. Using the concept of ligand field, the Slater-Condon integrals, the spin-orbit coupling constants, and the parameters of the ligand field potential are determined from density functional theory (DFT). Therefore, a theoretical procedure using LFDFT is established illustrating the spectroscopic details at the atomic scale that can be valuable in the analysis and characterization of the electronic spectra obtained from X-ray absorption fine structure or electron energy loss spectroscopies. Keywords Ligand field density functional theory (LFDFT) .Three-open-shell electron configuration . Multiplet structure and electric-dipole allowed transitions

show abstract

A Modern First-Principles View on Ligand Field Theory Through the Eyes of Correlated Multireference Wavefunctions

Cited by 154 publications

References 172 publications

Effect of Low Spin Excited States for Magnetic Anisotropy of Transition Metal Mononuclear Single Molecule Magnets

Effect of Low Spin Excited States for Magnetic Anisotropy of Transition Metal Mononuclear Single Molecule Magnets

Units and Conversion Factors

Electronic fine structure calculation of metal complexes with three-open-shell s, d, and p configurations

Contact Info

Product

Resources

About