Accurate State Energetics in Spin-Crossover Systems using Pure Density Functional Theory

The energy difference between different spin states of systems with transition metals is an outstanding challenge for electronic structure calculation methods. The small energy difference between high- and low-spin states in spin-crossover systems makes most post-Hartree-Fock or Density Functional T...

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Detalles Bibliográficos
Autores: Gómez Coca, Silvia, Ruiz Sabín, Eliseo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:dnet:ubarcelona__::7c45b27952cbd0693c990069eadf8973
Acceso en línea:https://hdl.handle.net/2445/229523
Access Level:acceso abierto
Palabra clave:Anàlisi espinorial
Nivells d&apos
energia (Mecànica quàntica)
Spinor analysis
Energy levels (Quantum mechanics)
Descripción
Sumario:The energy difference between different spin states of systems with transition metals is an outstanding challenge for electronic structure calculation methods. The small energy difference between high- and low-spin states in spin-crossover systems makes most post-Hartree-Fock or Density Functional Theory-based methods provide inaccurate values. A test case of twenty systems showing spin transitions has been used to evaluate the accuracy of a new family of meta-GGA (Generalized Gradient Approximation) functionals. One of the functionals of this new family provides comparable or even better values to the best functional reported so far for this type of systems, the TPSSh hybrid meta-GGA functional, but without having to use the exact exchange term. It also improves the results obtained with the r<sup>2</sup>SCAN meta-GGA functional, which was the best alternative to the TPSSh hybrid functional. This makes it possible to calculate the spin energetics of any kind of compounds, especially large systems or those involving periodic structures where the exact exchange requires large computational resources.