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Spin resolved electron number distribution functions: how spins couple in real space
A Martín Pendás1, E Francisco, M A Blanco
1Departamento de Química Física y Analítica, Facultad de Química, Universidad de Oviedo, 33006-Oviedo, Spain. angel@fluor.quimica.uniovi.es
The Journal of Chemical Physics
|October 16, 2007
Summary
This study develops methods to map electron spin distributions in molecules, revealing how atoms influence spin coupling and showing an Aufbau-like rule for spin configurations, even in singlet states.
Area of Science:
- Quantum Chemistry
- Computational Chemistry
- Chemical Physics
Background:
- Understanding electron spin distribution is crucial for predicting molecular properties and reactivity.
- Current methods often struggle to provide a detailed spatial view of spin configurations, especially in complex systems.
Purpose of the Study:
- To develop and compute probabilities for partitioning electrons into spatial regions within molecules.
- To analyze the spatial distribution of electron spins, including spin-resolved electron number distribution functions.
- To investigate the influence of atomic in-vacuo preferences on molecular spin configurations.
Main Methods:
- Development of probability functions for arbitrary partitions of electrons (N(alpha)m(s)=12 and N(beta)m(s)=-12) into m spatial regions.
- Computation of these functions for both atomic and electron localization function (ELF) basins.
- Application to a range of test systems.
Main Results:
- Spin-resolved electron number distribution functions provide coarse-grained spatial spin distribution, even for singlet states.
- Atoms within molecules partially retain their intrinsic spin configuration preferences.
- Evidence of long-range spin coupling among basins was observed.
- An Aufbau-like rule favoring spin coupling was identified, particularly for Hartree-Fock wave functions.
Conclusions:
- The developed methods offer new insights into the spatial organization of electron spins in molecules.
- Atomic contributions to spin preferences persist within molecules, influencing spin coupling.
- The identified Aufbau-like rule provides a predictive principle for spin coupling in certain electronic structure calculations.
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