Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published October 2, 2006 | Supplemental Material
Journal Article Open

Influence of Hartree-Fock exchange on the calculated Mössbauer isomer shifts and quadrupole splittings in ferrocene derivatives using density functional theory

Abstract

Influence of molecular geometry, type of exchange-correlation functional, and contraction scheme of basis set applied at the iron nuclei have been tested in the calculation of ^(57)Fe Mössbauer isomer shifts and quadrupole splittings for a wide range of ligand types, as well as oxidation and spin states, in inorganic and organometallic systems. It has been found that uncontraction of the s-part of Wachter's full-electron basis set at the iron nuclei does not appreciably improve the calculated isomer shifts. The observed correlations for all tested sets of geometries are close to each other and predominantly depend on the employed exchange-correlation functional with B3LYP functional being slightly better as compared to BPW91. Both hybrid (B3LYP) and pure (BPW91) exchange-correlation functionals are suitable for the calculation of isomer shifts in organometallic compounds. Surprisingly, it has been found that the hybrid B3LYP exchange-correlation functional completely fails in accurate prediction of quadrupole splittings in ferrocenes, while performance of the pure BPW91 functional for the same systems was excellent. This observation has been explained on the basis of relationship between the amount of Hartree-Fock exchange involved in the applied exchange-correlation functional and the calculated HOMO-LUMO energy gap in ferrocenes. On the basis of this explanation, use of only pure exchange-correlation functionals has been suggested for accurate prediction of Mössbauer spectra parameters in ferrocenes.

Additional Information

© 2006 American Chemical Society. Received June 27, 2006. We thank Research Corporation (grant CC6766) and University of Minnesota (Grant-in-Aid to V.N.N.) for financial support and Minnesota Supercomputing Institute for the generous support of computer time. We also acknowledge Professor Eric Oldfield and Dr. Douglas Fox for the numerous discussions and interest.

Attached Files

Supplemental Material - ic061176qsi20060724_081557.pdf

Files

ic061176qsi20060724_081557.pdf
Files (101.3 kB)
Name Size Download all
md5:bf53a7659098188cab7ceecffc04ff69
101.3 kB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 18, 2023