𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Assessment of the performance of density-functional methods for calculations on iron porphyrins and related compounds

✍ Scribed by Meng-Sheng Liao; John D. Watts; Ming-Ju Huang

Publisher
John Wiley and Sons
Year
2006
Tongue
English
Weight
235 KB
Volume
27
Category
Article
ISSN
0192-8651

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The behaviors of a large number of GGA, meta‐GGA, and hybrid‐GGA density functionals in describing the spin‐state energetics of iron porphyrins and related compounds have been investigated. There is a large variation in performance between the various functionals for the calculations of the high‐spin state relative energies. Most GGA and meta‐GGA functionals are biased toward lower‐spin states and so fail to give the correct ground state for the high‐spin systems, for which the meta‐GGA functionals show more or less improvement over the GGA ones. The GGA functionals that use the OPTX correction for exchange show remarkably high performance for calculating the high‐spin state energetics, but their results for the intermediate‐spin states are somewhat questionable. A heavily parameterized GGA functional, HCTH/407, provides results which are in qualitative agreement with the experimental findings for the iron porphyrins [FeP, FeP(Cl), FeP(THF)~2~], but its relative energies for the high‐spin states are probably somewhat too low. The high‐spin state relative energies are then even more underestimated by the corresponding meta‐GGA functional τ‐HCTH. For the hybrid‐GGA functionals, the Hartree‐Fock (HF)‐type (or exact) exchange contribution strongly stabilizes the high‐spin states, and so the performance of such functionals is largely dependent upon the amount of the HF exchange admixture in them. The B3LYP, B97, B97‐1, and τ‐HCTH‐hyb functionals are able to provide a satisfactory description of the energetics of all the systems considered. © 2006 Wiley Periodicals, Inc. J Comput Chem 27:1577–1592, 2006

📜 SIMILAR VOLUMES

Performance assessment of density-functi
Performance assessment of density-functional methods for study of charge-transfer complexes
✍ Meng-Sheng Liao; Yun Lu; Steve Scheiner 📂 Article 📅 2003 🏛 John Wiley and Sons 🌐 English ⚖ 290 KB

## Abstract Various density functionals are applied to a number of weakly bound intermolecular π–π charge‐transfer (CT) complexes. Most functionals, including the recently developed __m__PWPW91 and __m__PW1PW91, grossly underestimate experimental excitation energies; good agreement is obtained only

On the performance of density functional
On the performance of density functional methods for describing atomic populations, dipole moments and infrared intensities
✍ Frank De Proft; Jan M.L. Martin; Paul Geerlings 📂 Article 📅 1996 🏛 Elsevier Science 🌐 English ⚖ 591 KB

Atomic populations according to the Mulliken, electrostatic, natural population, and atomic polar tensor (APT) definitions were evaluated for first-and second-row compounds using different correlated ab initio techniques, DFT methods, and basis sets. All definitions except MuUiken exhibit modest bas

Performance of time-dependent density fu
Performance of time-dependent density functional and Green functions methods for calculations of excitation energies in radicals and for Rydberg electronic states
✍ A. S. Zyubin; A. M. Mebel 📂 Article 📅 2003 🏛 John Wiley and Sons 🌐 English ⚖ 104 KB

## Abstract Time‐dependent density functional (TD‐DFT) and perturbation theory‐based outer valence Green functions (OVGF) methods have been tested for calculations of excitation energies for a set of radicals, molecules, and model clusters simulating points defects in silica. The results show that

On the accuracy of density functional th
On the accuracy of density functional theory for iron—sulfur clusters
✍ Robert K. Szilagyi; Mark A. Winslow 📂 Article 📅 2006 🏛 John Wiley and Sons 🌐 English ⚖ 880 KB

## Abstract A simple, yet powerful wave function manipulation method was introduced utilizing a generalized ionic fragment approach that allows for systematic mapping of the wave function space for multispin systems with antiferromagnetic coupling. The use of this method was demonstrated for develo

Experiments Towards the Formation of 1,6
Experiments Towards the Formation of 1,6-Dehydroquadricyclane and Density Functional Calculations on This and Related Molecules
✍ Susanne Glück-Walther; Oliver Jarosch; Günter Szeimies 📂 Article 📅 1998 🏛 John Wiley and Sons 🌐 English ⚖ 507 KB

quadricyclane (21c), whose NMR spectra could also be recorded. 21c was converted into the corresponding 1,6-disub-1,6-Dibromoquadricyclane (6) was obtained from norbornadiene (11) by hydroboration, oxidation of the diol 12 to the stituted quadricyclanes with D 2 O (87%), chlorotrimethylsilane (92%),

The performance of a variety of density
The performance of a variety of density functional and ab initio methods on the structural problem of beryllium borohydride
✍ Agnes Derecskei-Kovacs; Dennis S. Marynick 📂 Article 📅 1994 🏛 Elsevier Science 🌐 English ⚖ 561 KB

The Dm and Dgd isomers of beryllium borohydride (BeB,Hs ) have been studied with different ab initio and density functional techniques. Optimized geometries were obtained with a polarized split valence basis set and electronic energies were calculated at the optimum geometry with an extended polariz