Simulation of heme using DFT + U: A step toward accurate spin-state energetics
We investigate the DFT + U approach as a viable solution to describe the low-lying states of ligated and unligated iron heme complexes. Besides their central role in organometallic chemistry, these compounds represent a paradigmatic case where LDA, GGA, and common hybrid functionals fail to reproduc...
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2007
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v111_n25_p7384_Scherlis http://hdl.handle.net/20.500.12110/paper_15206106_v111_n25_p7384_Scherlis |
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paper:paper_15206106_v111_n25_p7384_Scherlis2023-06-08T16:18:57Z Simulation of heme using DFT + U: A step toward accurate spin-state energetics Complexation Molecular structure Nitrogen compounds Organometallics Porphyrins Quantum chemistry Molecular geometries Spin transitions Spin-state energetics Density functional theory We investigate the DFT + U approach as a viable solution to describe the low-lying states of ligated and unligated iron heme complexes. Besides their central role in organometallic chemistry, these compounds represent a paradigmatic case where LDA, GGA, and common hybrid functionals fail to reproduce the experimental magnetic splittings. In particular, the imidazole pentacoordinated heme is incorrectly described as a triplet by all usual DFT flavors. In this study, we show that a U parameter close to 4 eV leads to spin transitions and molecular geometries in quantitative agreement with experiments and that DFT + U represents an appealing tool in the description of iron porphyrin complexes, at a much reduced cost compared to correlated quantum-chemistry methods. The possibility of obtaining the U parameter from first principles is explored through a self-consistent linear-response formulation. We find that this approach, which proved to be successful in other iron systems, produces in this case some overestimation with respect to the optimal values of U. © 2007 American Chemical Society. 2007 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v111_n25_p7384_Scherlis http://hdl.handle.net/20.500.12110/paper_15206106_v111_n25_p7384_Scherlis |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Complexation Molecular structure Nitrogen compounds Organometallics Porphyrins Quantum chemistry Molecular geometries Spin transitions Spin-state energetics Density functional theory |
| spellingShingle |
Complexation Molecular structure Nitrogen compounds Organometallics Porphyrins Quantum chemistry Molecular geometries Spin transitions Spin-state energetics Density functional theory Simulation of heme using DFT + U: A step toward accurate spin-state energetics |
| topic_facet |
Complexation Molecular structure Nitrogen compounds Organometallics Porphyrins Quantum chemistry Molecular geometries Spin transitions Spin-state energetics Density functional theory |
| description |
We investigate the DFT + U approach as a viable solution to describe the low-lying states of ligated and unligated iron heme complexes. Besides their central role in organometallic chemistry, these compounds represent a paradigmatic case where LDA, GGA, and common hybrid functionals fail to reproduce the experimental magnetic splittings. In particular, the imidazole pentacoordinated heme is incorrectly described as a triplet by all usual DFT flavors. In this study, we show that a U parameter close to 4 eV leads to spin transitions and molecular geometries in quantitative agreement with experiments and that DFT + U represents an appealing tool in the description of iron porphyrin complexes, at a much reduced cost compared to correlated quantum-chemistry methods. The possibility of obtaining the U parameter from first principles is explored through a self-consistent linear-response formulation. We find that this approach, which proved to be successful in other iron systems, produces in this case some overestimation with respect to the optimal values of U. © 2007 American Chemical Society. |
| title |
Simulation of heme using DFT + U: A step toward accurate spin-state energetics |
| title_short |
Simulation of heme using DFT + U: A step toward accurate spin-state energetics |
| title_full |
Simulation of heme using DFT + U: A step toward accurate spin-state energetics |
| title_fullStr |
Simulation of heme using DFT + U: A step toward accurate spin-state energetics |
| title_full_unstemmed |
Simulation of heme using DFT + U: A step toward accurate spin-state energetics |
| title_sort |
simulation of heme using dft + u: a step toward accurate spin-state energetics |
| publishDate |
2007 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_15206106_v111_n25_p7384_Scherlis http://hdl.handle.net/20.500.12110/paper_15206106_v111_n25_p7384_Scherlis |
| _version_ |
1768544928647872512 |