| Full text | |
| Author(s): |
de Souza, Jhonathan Rosa
[1]
;
de Moraes, Matheus Morato F.
[2]
;
Aoto, Yuri Alexandre
[2]
;
Homem-de-Mello, Paula
[1]
Total Authors: 4
|
| Affiliation: | [1] Univ Fed ABC UFABC, Ctr Ciencias Nat & Humanas CCNH, Av Estados 5001, BR-09210580 Santo Andre, SP - Brazil
[2] Univ Fed ABC UFABC, Ctr Matemat Comp & Cognic CMCC, Av Estados 5001, BR-09210580 Santo Andre, SP - Brazil
Total Affiliations: 2
|
| Document type: | Journal article |
| Source: | Physical Chemistry Chemical Physics; v. 22, n. 41, p. 23886-23898, NOV 7 2020. |
| Web of Science Citations: | 1 |
| Abstract | |
In this article, we describe calculations on the absorption spectrum of cobalt(ii) porphyrin, using density functional (DFT) and multireference n-electron valence perturbation (NEVPT) theories. With these calculations, we describe the lowest-energy states of doublet and quartet spin multiplicities, the excited states that originate the Q and B bands of porphyrins, some higher-energy pi-pi{*} excitations and charge-transfer states, HOMO-LUMO gaps, and ionisation potentials. Results undoubtedly show that the position of B band is essentially independent on the DFT functional, while the Q band is better described by pure functionals, and these bands do not depend on the initial state of the transition (whether doublet or quartet) as well. However, other excitation energies, orbital energies, and ionisation potentials strongly depend on the functional, in some cases varying more than 2 eV. Based on these results we conclude that one should not use the UV-Vis spectrum of metalloporphyrins to benchmark density functionals, mainly those properties related to coordination with the metallic ion. Furthermore, the results show that functionals that yield correct spectra may be based on an incorrect ground state description. Moreover, we reinforce that one must be skeptical about the reference chosen to benchmark electronic structure calculations, such as DFT functionals and active spaces for multireference calculations. (AU) | |
| FAPESP's process: | 18/04617-6 - The differentiable manifolds of the electronic structure theory |
| Grantee: | Yuri Alexandre Aoto |
| Support Opportunities: | Scholarships in Brazil - Young Researchers |
| FAPESP's process: | 18/14629-1 - Diatomic molecules containing cobalt and their excited states |
| Grantee: | Matheus Morato Ferreira de Moraes |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |
| FAPESP's process: | 18/25576-6 - Studies on photophysical and energy transfer processes of photosensibilizers with emphasis in photodynamic therapy: an approach of first principles |
| Grantee: | Jhonathan Rosa de Souza |
| Support Opportunities: | Scholarships in Brazil - Doctorate (Direct) |
| FAPESP's process: | 17/21199-0 - The differentiable manifolds of the electronic structure theory |
| Grantee: | Yuri Alexandre Aoto |
| Support Opportunities: | Research Grants - Young Investigators Grants |