Assessing Excited State Energy Gaps with Time-Dependent Density Functional Theory on Ru(II) Complexes

Bibliographic Details
Title: Assessing Excited State Energy Gaps with Time-Dependent Density Functional Theory on Ru(II) Complexes
Authors: Atkins, Andrew J., Talotta, Francesco, Freitag, Leon, Boggio-Pasqua, Martial, González, Leticia
Source: J. Chem. Theory Comput. 13 (2017) 4123-4145
Publication Year: 2017
Collection: Physics (Other)
Subject Terms: Physics - Chemical Physics
More Details: A set of density functionals coming from different rungs on Jacob's ladder are employed to evaluate the electronic excited states of three Ru(II) complexes. While most studies on the performance of density functionals compare the vertical excitation energies, in this work we focus on the energy gaps between the electronic excited states, of the same and different multiplicity. Excited state energy gaps are important for example to determine radiationless transition probabilities. Besides energies, a functional should deliver the correct state character and state ordering. Therefore, wavefunction overlaps are introduced to systematically evaluate the effect of different functionals on the character of the excited states. As a reference, the energies and state characters from multi-state second-order perturbation theory complete active space (MS-CASPT2) are used. In comparison to MS-CASPT2, it is found that while hybrid functionals provide better vertical excitation energies, pure functionals typically give more accurate excited state energy gaps. Pure functionals are also found to reproduce the state character and ordering in closer agreement to MS-CASPT2 than the hybrid functionals.
Document Type: Working Paper
DOI: 10.1021/acs.jctc.7b00379
Access URL: http://arxiv.org/abs/1709.08052
Accession Number: edsarx.1709.08052
Database: arXiv
More Details
DOI:10.1021/acs.jctc.7b00379