Publication

Multiplets of free d- and f-metal ions: A systematic DFT study

Alain Borel
2006
Journal Articles

Abstract

In this work we apply in a systematic way our multi-determinantal model to calculate the fine structure of the whole atomic multiplet manifold. The key feature of this approach is the explicit treatment of near-degeneracy correlation using ad hoc configuration interaction (CI) within the active space of Kohn–Sham (KS) orbitals with open d- or f-shells. The calculation of the CI-matrices is based on a central symmetry decomposition of the energies of all single determinants (micro-states) calculated according to Density Functional Theory (DFT) for frozen KS-orbitals corresponding to the averaged configuration, eventually with fractional occupations, of the d- or f-orbitals and/or the direct calculation of the electrostatic reduced matrix elements (Racah or Slater–Condon parameters) occurring in the corresponding active space. We performed DFT calculations on all divalent and trivalent d^2–d^8 metal ions, as well as the f^2–f^12 lanthanide(III) ions. We compare the results of both variants of the method with the data available in the literature. Both procedures yield multiplet energies with an accuracy of about hundred wave numbers and fine structure splitting accurate to less than a tenth of this amount.

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https://infoscience.epfl.ch/entities/publication/362ba783-1d32-4286-b6da-c11c82d9d42f

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Alain Borel
2006
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/362ba783-1d32-4286-b6da-c11c82d9d42f

About this result

Ontological neighbourhood

Chemistry

Computational chemistry: Topics in computational chemistry

Related concepts (32)

Molecular orbital

In chemistry, a molecular orbital (ɒrbədl) is a mathematical function describing the location and wave-like behavior of an electron in a molecule. This function can be used to calculate chemical and physical properties such as the probability of finding an electron in any specific region. The terms atomic orbital and molecular orbital were introduced by Robert S. Mulliken in 1932 to mean one-electron orbital wave functions. At an elementary level, they are used to describe the region of space in which a function has a significant amplitude.

Ion

An ion (ˈaɪ.ɒn,_-ən) is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons.

Density functional theory

Density-functional theory (DFT) is a computational quantum mechanical modelling method used in physics, chemistry and materials science to investigate the electronic structure (or nuclear structure) (principally the ground state) of many-body systems, in particular atoms, molecules, and the condensed phases. Using this theory, the properties of a many-electron system can be determined by using functionals, i.e. functions of another function. In the case of DFT, these are functionals of the spatially dependent electron density.

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