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Detailed Pair Natural Orbital-Based Coupled Cluster Studies of Spin Crossover Energetics

[Image: see text] In this work, a detailed study of spin-state splittings in three spin crossover model compounds with DLPNO-CCSD(T) is presented. The performance in comparison to canonical CCSD(T) is assessed in detail. It was found that spin-state splittings with chemical accuracy, compared to the...

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Autores principales: Flöser, Benedikt M., Guo, Yang, Riplinger, Christoph, Tuczek, Felix, Neese, Frank
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2020
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7310951/
https://www.ncbi.nlm.nih.gov/pubmed/32196337
http://dx.doi.org/10.1021/acs.jctc.9b01109
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author Flöser, Benedikt M.
Guo, Yang
Riplinger, Christoph
Tuczek, Felix
Neese, Frank
author_facet Flöser, Benedikt M.
Guo, Yang
Riplinger, Christoph
Tuczek, Felix
Neese, Frank
author_sort Flöser, Benedikt M.
collection PubMed
description [Image: see text] In this work, a detailed study of spin-state splittings in three spin crossover model compounds with DLPNO-CCSD(T) is presented. The performance in comparison to canonical CCSD(T) is assessed in detail. It was found that spin-state splittings with chemical accuracy, compared to the canonical results, are achieved when the full iterative triples (T(1)) scheme and TightPNO settings are applied and relativistic effects are taken into account. Having established the level of accuracy that can be reached relative to the canonical results, we have undertaken a detailed basis set study in the second part of the study. The slow convergence of the results of correlated calculations with respect to basis set extension is particularly acute for spin-state splittings for reasons discussed in detail in this Article. In fact, for some of the studied systems, 5Z basis sets are necessary in order to come close to the basis set limit that is estimated here by basis set extrapolation. Finally, the results of the present work are compared to available literature. In general, acceptable agreement with previous CCSD(T) results is found, although notable deviations stemming from differences in methodology and basis sets are noted. It is noted that the published CASPT2 numbers are far away from the extrapolated CCSD(T) numbers. In addition, dynamic quantum Monte Carlo results differ by several tens of kcal/mol from the CCSD(T) numbers. A comparison to DFT results produced with a range of popular density functionals shows the expected scattering of results and showcases the difficulty of applying DFT to spin-state energies.
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spelling pubmed-73109512020-06-24 Detailed Pair Natural Orbital-Based Coupled Cluster Studies of Spin Crossover Energetics Flöser, Benedikt M. Guo, Yang Riplinger, Christoph Tuczek, Felix Neese, Frank J Chem Theory Comput [Image: see text] In this work, a detailed study of spin-state splittings in three spin crossover model compounds with DLPNO-CCSD(T) is presented. The performance in comparison to canonical CCSD(T) is assessed in detail. It was found that spin-state splittings with chemical accuracy, compared to the canonical results, are achieved when the full iterative triples (T(1)) scheme and TightPNO settings are applied and relativistic effects are taken into account. Having established the level of accuracy that can be reached relative to the canonical results, we have undertaken a detailed basis set study in the second part of the study. The slow convergence of the results of correlated calculations with respect to basis set extension is particularly acute for spin-state splittings for reasons discussed in detail in this Article. In fact, for some of the studied systems, 5Z basis sets are necessary in order to come close to the basis set limit that is estimated here by basis set extrapolation. Finally, the results of the present work are compared to available literature. In general, acceptable agreement with previous CCSD(T) results is found, although notable deviations stemming from differences in methodology and basis sets are noted. It is noted that the published CASPT2 numbers are far away from the extrapolated CCSD(T) numbers. In addition, dynamic quantum Monte Carlo results differ by several tens of kcal/mol from the CCSD(T) numbers. A comparison to DFT results produced with a range of popular density functionals shows the expected scattering of results and showcases the difficulty of applying DFT to spin-state energies. American Chemical Society 2020-03-20 2020-04-14 /pmc/articles/PMC7310951/ /pubmed/32196337 http://dx.doi.org/10.1021/acs.jctc.9b01109 Text en Copyright © 2020 American Chemical Society This is an open access article published under a Creative Commons Attribution (CC-BY) License (http://pubs.acs.org/page/policy/authorchoice_ccby_termsofuse.html) , which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
spellingShingle Flöser, Benedikt M.
Guo, Yang
Riplinger, Christoph
Tuczek, Felix
Neese, Frank
Detailed Pair Natural Orbital-Based Coupled Cluster Studies of Spin Crossover Energetics
title Detailed Pair Natural Orbital-Based Coupled Cluster Studies of Spin Crossover Energetics
title_full Detailed Pair Natural Orbital-Based Coupled Cluster Studies of Spin Crossover Energetics
title_fullStr Detailed Pair Natural Orbital-Based Coupled Cluster Studies of Spin Crossover Energetics
title_full_unstemmed Detailed Pair Natural Orbital-Based Coupled Cluster Studies of Spin Crossover Energetics
title_short Detailed Pair Natural Orbital-Based Coupled Cluster Studies of Spin Crossover Energetics
title_sort detailed pair natural orbital-based coupled cluster studies of spin crossover energetics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7310951/
https://www.ncbi.nlm.nih.gov/pubmed/32196337
http://dx.doi.org/10.1021/acs.jctc.9b01109
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