Molecular DFT+U: A Transferable, Low-Cost Approach to Eliminate Delocalization Error
Name
2103.06781.pdf
Description
Submitted version
Size
3.24 MB
Format
Adobe PDF
Checksum (MD5)
0d7d41383348ec555fb5c3abce46ed70
Author(s)
Bajaj, Akash
Kulik, Heather J
Date Issued
2021
Journal
Journal of Physical Chemistry Letters
Publisher
American Chemical Society (ACS)
Version
Original manuscript
Abstract
While density functional theory (DFT) is widely applied for its combination
of cost and accuracy, corrections (e.g., DFT+U) that improve it are often
needed to tackle correlated transition-metal chemistry. In principle, the
functional form of DFT+U, consisting of a set of localized atomic orbitals (AO)
and a quadratic energy penalty for deviation from integer occupations of those
AOs, enables the recovery of the exact conditions of piecewise linearity and
the derivative discontinuity. Nevertheless, for practical transition-metal
complexes, where both atomic states and ligand orbitals participate in bonding,
standard DFT+U can fail to eliminate delocalization error (DE). Here, we show
that by introducing an alternative valence-state (i.e., molecular orbital or
MO) basis to the DFT+U approach, we recover exact conditions in cases where
standard DFT+U corrections have no error-reducing effect. This MO-based DFT+U
also eliminates DE where standard AO-based DFT+U is already successful. We
demonstrate the transferability of our approach on a range of ligand field
strengths (i.e., from H_2O to CO), electron configurations (i.e., from Sc to Fe
to Zn), and spin states (i.e., low-spin and high-spin) in representative
transition-metal complexes.
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1021/acs.jpclett.1c00796
