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Published on: January 9, 2014
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The Spin-Partitioned Total-Position Spread Tensor: An Application To Diatomic Molecules.
Oriana Brea1,2, Muammar El Khatib1, Gian Luigi Bendazzoli3
1Laboratoire de Chimie et Physique Quantiques-LCPQ/IRSAMC, Université de Toulouse (UPS) et CNRS (UMR-5626) , 118, Route de Narbonne, Toulouse Cedex 31062, France.
The Journal of Physical Chemistry. A
|March 26, 2016
Summary
The spin partition of the total-position spread tensor reveals spin delocalization in molecules. This method complements charge mobility insights, offering a deeper understanding of chemical bond behavior and molecular electronic structure.
Area of Science:
- Quantum Chemistry
- Computational Chemistry
- Molecular Physics
Background:
- The total-position spread (TPS) tensor describes molecular charge mobility.
- Understanding electron distribution and bonding requires methods beyond charge mobility.
Purpose of the Study:
- To apply the spin partition (SP) of the TPS tensor to light diatomic molecules.
- To investigate the complementary information provided by SP-TPS compared to spin-summed (SS) quantities.
- To analyze spin delocalization and its relation to chemical bonding.
Main Methods:
- Full Configuration Interaction (FCI) calculations.
- Application of the spin partition (SP) to the total-position spread (TPS) tensor.
- Analysis of spin-summed (SS-TPS) and spin-partitioned (SP-TPS) tensors.
Main Results:
- SP-TPS provides insights into spin delocalization, complementary to SS-TPS which describes charge mobility.
- The component along the chemical bond (Λ(∥)) is crucial for both tensors.
- SP-TPS exhibits distinct behaviors for covalent (squared growth) and ionic bonds (faster-than-linear growth).
- SP-TPS effectively describes the spin delocalization in weakly bonded molecules like He2 and Be2, highlighting their multireference character.
Conclusions:
- The SP-TPS tensor is a valuable tool for characterizing spin delocalization in molecules.
- The behavior of SP-TPS along the bond axis is sensitive to the type of chemical interaction.
- SP-TPS analysis provides deeper insights into the electronic structure of challenging systems, including those with multireference character.
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