Abstract
The solvation structure of transition metal ions is important for applications in geochemistry, biochemistry, energy storage, and environmental chemistry. We study the X-ray absorption pre-edge and near-edge spectra at the K-edge of a nearly complete series of hydrated first-row transition metal ions with d orbital occupancy from d2to d10. We optimize all of the structures at the density functional theory (DFT) level with explicit solvation and then compute the pre-edge X-ray absorption spectra with time-dependent DFT (TDDFT) and restricted active space second-order perturbation theory (RASPT2). TDDFT provides accurate results for spectra that are dominated by single excitations, while RASPT2 correctly distinguishes between singly and doubly excited states with quantitative accuracy compared with experiment. We analyze the pre-edge features for each metal ion to reveal the impact of the variations in d orbital occupancy on the first-shell coordination environment. We also report the lowest-energy ligand field d-d transitions using complete active space second-order perturbation theory.
| Original language | English |
|---|---|
| Pages (from-to) | 6323-6330 |
| Number of pages | 8 |
| Journal | Journal of Physical Chemistry Letters |
| Volume | 13 |
| Issue number | 27 |
| DOIs | |
| State | Published - Jul 14 2022 |
Funding
This work was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, under Grants 72685 (S.G. and N.G.) and 16248 (M.G. and J.L.F.). H.A. and N.S. acknowledge support from a University of Michigan Office of Research Grant (UMOR-29814) and start-up funds of N.S. H.A. and N.S. also thank Dr. Chengjun Sun for his help in the collection of V XANES. This research benefited from computational resources provided by EMSL, a DOE Office of Science User Facility sponsored by the Office of Biological and Environmental Research and located at PNNL. PNNL is operated by Battelle Memorial Institute for the DOE under DOE Contract DE-AC05-76RL1830. This research also used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. DOE Office of Science User Facility operated under Contract DE-AC02-05CH11231. This research used resources of Advanced Photon Source Sector 20, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract DE-AC02-06CH11357, and the Canadian Light Source and its funding partners. 4+