scholarly journals Configuration-averaged 4f orbitals in ab initio calculations of low-lying crystal field levels in lanthanide(iii) complexes

2016 ◽  
Vol 18 (23) ◽  
pp. 15807-15814 ◽  
Author(s):  
Willem Van den Heuvel ◽  
Simone Calvello ◽  
Alessandro Soncini
Keyword(s):  
Magnetic Properties ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Crystal Field ◽  
Lanthanide Complexes

We propose an ab initio method that simplifies the CASSCF/RASSI–SO approach for crystal field levels and magnetic properties of lanthanide complexes.

scholarly journals Ab Initio Non-Covalent Crystal Field Theory for Lanthanide Complexes: A Multiconfigurational Non-Orthogonal Group Functions Approach

2020 ◽  
Author(s):  
Alessandro Soncini ◽  
MATTEO PICCARDO
Keyword(s):  
Magnetic Properties ◽  
Perturbation Theory ◽  
Ab Initio ◽  
Crystal Field ◽  
Orthogonal Group ◽  
Lanthanide Complexes ◽  
Field Energy ◽  
First Order ◽  
Group Functions ◽  
Metal Ligand

We present a non-orthogonal fragment ab initio methodology for the calculation of crystal field energy levels and magnetic properties in lanthanide complexes, implementing a systematic description of non-covalent contributions to metal-ligand bonding. The approach has two steps. In the first step, appropriate ab initio wavefunctions for the various ionic fragments (lanthanide ion and coordinating ligands) are separately optimized, accounting for the electrostatic influence of the surrounding environment, within various approximations. In the second and final step, the scalar relativistic (DKH2) electrostatic Hamiltonian of the whole molecule is represented on the basis of the optimized metal-ligand multiconfigurational non-orthogonal group functions (MC-NOGF), and reduced to an effective (2J+1)-dimensional non-orthogonal Configuration Interaction (CI) problem via L{\"o}wdin-partitioning. Within the proposed formalism, the projected Hamiltonian can be implemented to any desired order of perturbation theory in the fragment-localised excitations out of the degenerate space, and its eigenvalues and eigenfunctions are systematic approximations to the crystal field energies and wavefunctions. We present a preliminary implementation of the proposed MC-NOGF method to first-order degenerate perturbation theory within our own ab initio code CERES, and compare its performance both with the simpler non-covalent orthogonal ab initio approach Fragment Ab Initio Model Potential (FAIMP) approximation, and with the full CAHF/CASCI-SO method, accounting for metal-ligand covalency in a mean-field manner. We find that energies and magnetic properties for 44 complexes obtained via an iteratively optimized version of our MC-NOGF first-order non-covalent method, compare remarkably well to the full CAHF/CASCI-SO method including metal-ligand covalency, and are superior to the best purely electrostatic results achieved via an iteratively optimized version of the FAIMP approach.<br>

scholarly journals Luminescence, Chiroptical, Magnetic and Ab-Initio Crystal-Field Characterizations of an Enantiopure Helicoidal Yb(III) Complex: The Van Vleck Rennaissance

2020 ◽  
Author(s):  
Frédéric Gendron ◽  
Sebastiano Di Pietro ◽  
Laura Abad Galan ◽  
François Riobé ◽  
Virginie Placide ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
High Resolution ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Crystal Field ◽  
Chiroptical Properties ◽  
Spectroscopic Measurements ◽  
Combined Use ◽  
Van Vleck

<p>The electronic structure of a chiral Yb(III)-based complex is fully determined by taking advantage of experimental magnetic, luminescence, and chiroptical characterizations in combination with ab-initio wavefunction calculations. The combined use of these techniques allows determining with high resolution the electronic structure diagram as well as the nature of the different states involved in the magnetic and chiroptical properties of the investigated complex. The different crystal-field pictures deduced from spectroscopic measurements are re-conciliated in light of the magnetic properties and ab-initio results in the frame of the van Vleck initial vision. Advanced ab-initio calculations demonstrate that global chiroptical spectra correspond to the sum of intricated transitions with similar or opposite polarizations.</p>

scholarly journals Ab Initio Non-Covalent Crystal Field Theory for Lanthanide Complexes: A Multiconfigurational Non-Orthogonal Group Functions Approach

2020 ◽  
Author(s):  
Alessandro Soncini ◽  
MATTEO PICCARDO
Keyword(s):  
Magnetic Properties ◽  
Perturbation Theory ◽  
Ab Initio ◽  
Crystal Field ◽  
Orthogonal Group ◽  
Lanthanide Complexes ◽  
Field Energy ◽  
First Order ◽  
Group Functions ◽  
Metal Ligand

We present a non-orthogonal fragment ab initio methodology for the calculation of crystal field energy levels and magnetic properties in lanthanide complexes, implementing a systematic description of non-covalent contributions to metal-ligand bonding. The approach has two steps. In the first step, appropriate ab initio wavefunctions for the various ionic fragments (lanthanide ion and coordinating ligands) are separately optimized, accounting for the electrostatic influence of the surrounding environment, within various approximations. In the second and final step, the scalar relativistic (DKH2) electrostatic Hamiltonian of the whole molecule is represented on the basis of the optimized metal-ligand multiconfigurational non-orthogonal group functions (MC-NOGF), and reduced to an effective (2J+1)-dimensional non-orthogonal Configuration Interaction (CI) problem via L{\"o}wdin-partitioning. Within the proposed formalism, the projected Hamiltonian can be implemented to any desired order of perturbation theory in the fragment-localised excitations out of the degenerate space, and its eigenvalues and eigenfunctions are systematic approximations to the crystal field energies and wavefunctions. We present a preliminary implementation of the proposed MC-NOGF method to first-order degenerate perturbation theory within our own ab initio code CERES, and compare its performance both with the simpler non-covalent orthogonal ab initio approach Fragment Ab Initio Model Potential (FAIMP) approximation, and with the full CAHF/CASCI-SO method, accounting for metal-ligand covalency in a mean-field manner. We find that energies and magnetic properties for 44 complexes obtained via an iteratively optimized version of our MC-NOGF first-order non-covalent method, compare remarkably well to the full CAHF/CASCI-SO method including metal-ligand covalency, and are superior to the best purely electrostatic results achieved via an iteratively optimized version of the FAIMP approach.<br>

scholarly journals Luminescence, Chiroptical, Magnetic and Ab-Initio Crystal-Field Characterizations of an Enantiopure Helicoidal Yb(III) Complex: The Van Vleck Rennaissance

2020 ◽  
Author(s):  
Frédéric Gendron ◽  
Sebastiano Di Pietro ◽  
Laura Abad Galan ◽  
François Riobé ◽  
Virginie Placide ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
High Resolution ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Crystal Field ◽  
Chiroptical Properties ◽  
Spectroscopic Measurements ◽  
Combined Use ◽  
Van Vleck

<p>The electronic structure of a chiral Yb(III)-based complex is fully determined by taking advantage of experimental magnetic, luminescence, and chiroptical characterizations in combination with ab-initio wavefunction calculations. The combined use of these techniques allows determining with high resolution the electronic structure diagram as well as the nature of the different states involved in the magnetic and chiroptical properties of the investigated complex. The different crystal-field pictures deduced from spectroscopic measurements are re-conciliated in light of the magnetic properties and ab-initio results in the frame of the van Vleck initial vision. Advanced ab-initio calculations demonstrate that global chiroptical spectra correspond to the sum of intricated transitions with similar or opposite polarizations.</p>

Study of Electronic and Magnetic Properties of Zn1−x M x O (M = Mn and Cr) by ab initio Calculations

2013 ◽  
Vol 26 (12) ◽  
pp. 3469-3474 ◽  
Author(s):  
A. Rkhioui ◽  
R. Masrour ◽  
E. K. Hlil ◽  
L. Bahmad ◽  
M. Hamedoun ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electronic And Magnetic Properties

Geometric and electronic structure and magnetic properties of Fe–Au nanoalloys: insights from ab initio calculations

2015 ◽  
Vol 17 (42) ◽  
pp. 28177-28185 ◽  
Author(s):  
Sampyo Hong ◽  
Talat S. Rahman
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Magnetic Moment ◽  
Au Nanoparticles

Fe–Au nanoparticles maintain almost a constant magnetic moment of ∼2.8 μB, which is 27% enhancement from the bulk value.

scholarly journals Slow Relaxation of the Magnetization in Bis-Decorated Chiral Helicene-Based Coordination Complexes of Lanthanides

2018 ◽  
Vol 4 (3) ◽  
pp. 39 ◽  
Author(s):  
Jessica Flores Gonzalez ◽  
Vincent Montigaud ◽  
Nidal Saleh ◽  
Olivier Cador ◽  
Jeanne Crassous ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Single Molecule ◽  
Crystalline Phase ◽  
Coordination Complexes ◽  
Slow Relaxation ◽  
Single Molecule Magnets ◽  
Racemic Form

The complexes [Ln2(hfac)6(L)]·nC6H14 (Ln = Dy (1) n = 0, Yb (2) n = 1) with the L chiral 3,14-di-(2-pyridyl)-4,13-diaza[6]helicene ligand (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate) have been synthesized in their racemic form and structurally and magnetically characterized. Both complexes behave as field-induced single molecule magnets in the crystalline phase. These magnetic properties were rationalized by ab initio calculations.

Study of the Magnetic Properties of CdMnTe1−y N y and CdMnTe with Defects by Ab Initio Calculations

2015 ◽  
Vol 28 (12) ◽  
pp. 3545-3552 ◽  
Author(s):  
A. Ait Raiss ◽  
Y. Sbai ◽  
Z. Zarhri ◽  
L. Bahmad ◽  
A. Benyoussef
Keyword(s):  
Magnetic Properties ◽  
Ab Initio Calculations ◽  
Ab Initio

Ligand field fine-tuning on the modulation of the magnetic properties and relaxation dynamics of dysprosium(iii) single-ion magnets (SIMs): synthesis, structure, magnetism and ab initio calculations

2017 ◽  
Vol 5 (6) ◽  
pp. 1369-1382 ◽  
Author(s):  
Sheng Zhang ◽  
Haipeng Wu ◽  
Lin Sun ◽  
Hongshan Ke ◽  
Sanping Chen ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Theoretical Investigation ◽  
Fine Tuning ◽  
Ligand Field ◽  
Relaxation Dynamics ◽  
Controllable Synthesis

For dysprosium(iii) single-ion magnets (SIMs), it is crucial to explore their controllable synthesis and conduct a systematic theoretical investigation.

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