Version 3.1 of the TheoDORE wavefunction analysis package is available. Download the current version below.
Download the newest release of the TheoDORE wavefunction analysis program – TheoDORE 3.2 (22 July 2024)
Our work has been accepted as cover art for Chemical Science. The figure shows an inositol phosphate binding to a lanthanide receptor molecule inducing a fluorescent respose.
The cover art illustrates the work Expedient synthesis and luminescence sensing of the inositol pyrophosphate cellular messenger 5-PP-InsP5 led by Stephen Butler at Loughborough and Barry Potter at Oxford.
A recent JPCA article by Karadakov and Al-Yassiri highlights the differences in singlet and triplet aromaticity in naphthalene. To me this paper contains several striking observations:
We have discussed the excited states of naphthalene from an entirely different viewpoint in a recent J. Chem. Theory Comput. article. It would be fascinating to combine the two viewpoints.
We just posted a preprint discussing a question I have been wondering about for a while: Why is the lowest excited state of a molecule not always the HOMO/LUMO transition? More generally we show how singlet and triplet state energies are affected in different ways by post-MO energy terms.
The preprint can be found here: Excited-state energy component analysis for molecules – Why the lowest excited state is not always the HOMO-LUMO transition
Update: the final published version is available here.
A new book chapter by Patrick and Felix just appeared online: “Classification and Analysis of Molecular Excited States“. Ultimately, this chapter will be part of the Comprehensive Computational Chemistry series published by Elsevier.
In this chapter we explore the various ways in which excited states are classified, that is, according to
The map below shows the different classes and highlights the multitude of ways that are used to discuss excited states in the literature.
It is the purpose of this chapter to discuss all these types of states, covering the mathematical and physical background as well as the consequences to spectroscopy and photochemistry.
Our new paper “Classification of Doubly Excited Molecular Electronic States” just appeared in Chemical Science.
The topic of doubly excited states has been discussed quite controversially in the literature over the last couple of years, see for example JACS, 139, 13770 (2017) and JCTC 14, 9 (2018), and it is often disputed whether to classify a state as doubly excited at all. To contribute to this discussion we worked on the development of a physically motivated definition of doubly excited character based on operator expectation values and density matrices, which works independently of the underlying orbital representation. We hope that this approach will provide new understanding on these issues.
I enjoyed this paper from the Grimme group:
Best-Practice DFT Protocols for Basic Molecular Computational Chemistry, Angew. Chem. Int. Ed., 2022, 61, e202205735.
The authors discuss the best modern methods for running a DFT computations – a guide through the jungle. For me the main conclusions regarding functionals are:
A new funded PhD position is available in the group: Computational design of functional molecular materials.
This is a flexible position allowing you to apply state-of-the-art quantum chemistry along with sophisticated analysis methods. The goal is to develop new rules for designing functional materials going beyond the frontier orbital picture. The work will apply rules developed in PCCP, 22, 6058-6080 (2020) in connection with experimental partners.
This is a flexible studentship that can be adjusted to your needs and interests. Please apply by February 2023 if this interests you.
Today, Felix will present at the School on High-Performance Multilayer Molecular Dynamics Approaches in Madrid. He will talk about classification and analysis of excited states in the morning, and present the practical use of TheoDORE in the afternoon. Please, see the official web page for online joining instructions.
Kasha’s rule states that fluorescence generally occurs from the lowest excited singlet state (S1). Exceptions to this rule are usually associated with a metastable S2 state that is separated from S1 not allowing for interconversion. In a recent article we outlined a different mechanism for non-Kasha fluorescence: If S1 and S2 are very close in energy, then S2 is populated in a dynamic equilibrium following Boltzmann statistics. This effect is particularly pronounced if there is a large amount of vibrational excess energy following excitation into a high-energy absorption peak. The full story, “Non-Kasha fluorescence of pyrene emerges from a dynamic equilibrium between excited states” was just published in J. Chem. Phys.