A multireference excited state database for correlation-aware screening of organic semiconductors in excitonic energy-materials discovery

Tools

Zollner, Malin and Nematiaram, Tahereh (2026) A multireference excited state database for correlation-aware screening of organic semiconductors in excitonic energy-materials discovery. In: AIChemy ECR Exchange: Scotland, 2026-06-02, University of Strathclyde.

[thumbnail of Zollner-Nematiaram-AIC-ECRE-2026-A-Multireference-Excited-State-Database-for-Correlation-Aware]
Preview
 Text. Filename: Zollner-Nematiaram-AIC-ECRE-2026-A-Multireference-Excited-State-Database-for-Correlation-Aware.pdf
Accepted Author Manuscript
License: Creative Commons Attribution 4.0 logo
Download (1MB)| Preview

Abstract

Organic semiconductors are attractive molecular platforms for excitonic energy materials, including light-harvesting, photon-management and energy-relevant optoelectronic technologies, but their discovery depends on reliable excited-state screening across large and chemically diverse molecular spaces. Here, we develop a multireference excited-state database for 1,581 organic semiconductors to benchmark screening descriptors that control energy-relevant photophysical behaviour. For each molecule, we compute the two lowest singlet and triplet excitation energies and the oscillator strengths of the two lowest singlet transitions using the multireference methods SA-CASSCF and SC-NEVPT2, and compare these data with existing single-reference TD-DFT screening results. This comparison shows that TD-DFT provides a useful low-cost route for broad prescreening, particularly for more robust descriptors such as triplet excitation energies, while singlet excitation energies, oscillator strengths, singlet--triplet gaps and singlet--singlet separations are more sensitive to electron correlation. The largest method-dependent deviations occur for electronically soft, heteroatom-rich, sulfur-containing and acyclic conjugated scaffolds, whereas rigid aromatic cores are more transferable across levels of theory. These differences have direct consequences for materials discovery: relative to TD-DFT prescreening, SC-NEVPT2 expands the chemically diverse thermally activated delayed fluorescence candidate space, identifies optically relevant inverted singlet--triplet-gap molecules and broadens the scaffold diversity of anti-Kasha candidates. By establishing where routine screening is reliable and where multireference validation reveals additional opportunities, this database provides a practical correlation-aware framework for discovering organic semiconductors for excitonic energy-materials applications.

ORCID iDs

Zollner, Malin ORCID logoORCID: https://orcid.org/0009-0000-9662-0869 and Nematiaram, Tahereh ORCID logoORCID: https://orcid.org/0000-0002-0371-4047;
  • Item type:Conference or Workshop Item(Poster)
    ID code:96412
    Dates:
    Date
    Event
    2 June 2026
    Published
    Subjects:Science > Chemistry
    Department:Faculty of Science > Pure and Applied Chemistry
    Depositing user: Pure Administrator
    Date deposited:04 Jun 2026 11:15
    Last modified:29 Jun 2026 08:37
    URI:https://strathprints.strath.ac.uk/id/eprint/96412
CORE (COnnecting REpositories)