A paper co-authored by Felix has been featured as the top highly cited paper in J. Chem. Theory Comput. for 2018. Our paper “Benchmarking Excited-State Calculations Using Exciton Properties” has received 22 citations since its publication in early 2018. The paper deals with the question of how we can assess the reliability of excited-state computations in a rigorous and reproducible fashion.
Author: Felix
Talks: Marseille and Montpellier
This week Felix will give a seminar talks at Marseille and Montpellier entitled”New Tools for Computational Photochemistry: Wavefunction Analysis and Dynamics.” The talk briefly summarises a number of computational methods developed.
Wavefunction analysis methods:
Methods for nonadiabatic dynamics simulations:
- Dynamics with correlated single-reference methods [Ref1, Ref2]
- Wavefunction overlaps
- Model potentials: linear vibronic coupling and Frenkel exciton models
You can download the slides here:
Talk: Ionic and covalent states
Tomorrow, Felix will give a talk at the Computational Molecular Science Meeting in Warwick: “Understanding ionic and covalent wavefunction character without valence bond theory”.
The talk presents some new ideas on a long-standing question in computational chemistry, the connection between valence-bond theory and molecular orbital theory. In particular, the talk will be explore how two concepts from valence-bond theory, ionic and covalent wavefunction character, can be reconstructed from general quantum chemistry computations performed in the molecular orbital picture. The talk is based on the following paper in ChemPhotoChem.
You can download the slides here:
Preprint: Two-photon absorption
We just uploaded a preprint for our new paper: Effect of Symmetric and Asymmetric Substitution on the Optoelectronic Properties of 9,10-Dicyanoanthracene onto ChemarXiv. Take a look if you are interested in optical materials and two-photon absorbers.
Paper: Visualisation of electron correlation
Felix’s first purely Loughborough grown paper just appeared as a Communication in ChemPhotoChem: “Visualisation of Electronic Excited‐State Correlation in Real Space“. The paper explores a new method for visualising electron correlation exemplified in the case excited states represented in the electron/hole picture. The idea is to fix the hole on one fragment of the system and to observe how the excited electron adjusts to this position.
Below, I am showing this analysis for the lowest 10 excited states of the system. The hole (shown in red) is always located on the second thiophene unit from the right. The electron (shown in blue) adjusts in different ways to this hole position, either moving toward it or going away from it.
As shown above, the method offers a new and intuitive way of viewing correlated exciton wavefunctions. It was also shown in this paper how the method allows to naturally distinguish between ionic and covalent states of naphthalene without any explicit reference to valence bond theory.
Talk: New Tools for Computational Photochemistry
Tomorrow, Felix will give a seminar talk at the University of Nottingham – “New Tools for Computational Photochemistry: Wavefunction Analysis and Dynamics.” The talk briefly summarises a number of computational methods developed.
Wavefunction analysis methods:
- Charge-transfer numbers
- Conditional electron densities
- Quantitative exciton properties
Methods for nonadiabatic dynamics simulations:
- Dynamics with correlated single-reference methods [Ref1, Ref2]
- Wavefunction overlaps
- Model potentials: linear vibronic coupling and Frenkel exciton models
You can download the slides here:
Poster: Boosting the efficiency of nonadiabatic dynamics simulations
On 8th January, Felix will present a poster entitled “Boosting the efficiency of nonadiabatic dynamics simulations” at the RSC Spectroscopy and Dynamics Group meeting in Nottingham. This poster will discuss how the efficiency of nonadiabatic dynamics simulations can be dramatically enhanced by using model potentials. Two recent papers, showing the application of vibronic coupling models and Frenkel exciton models will be discussed.
You can download the poster here:
Midlands Computational Chemistry Meeting 2019
The date and place for the Midlands Computational Chemistry Meeting 2019 are fixed. The meeting will take place on 15 April 2019 at Loughborough University in West Park Teaching Hub. You can find the details here.
Paper: Two-Photon Polymerisation Initiators
A joint experimental and computational study with groups from Vienna and Geneva just appeared in Sci. Rep.: “Wavelength-optimized Two-Photon Polymerization Using Initiators Based on Multipolar Aminostyryl-1,3,5-triazines.” In this paper, the two-photon absorption properties of a new class of aminostyryl-triazines were investigated showing good agreement between experiment and computation. Furthermore, the practical applicability of these molecules for 3D-printing was shown.
Paper: Dynamics within an Exciton Model
Another paper working on improving the efficiency of surface hopping dynamics just appeared, this time in JCTC: “Surface hopping within an exciton picture – An electrostatic embedding scheme.” authored by M. F. S. J. Menger, F. Plasser, B. Mennucci, and L. González. In this paper, we explored the possibility of running nonadiabatic dynamics simulations within an exciton model. The main challenge in this endeavour was to derive a consistent energy expression for combining QM/MM electrostatic embedding calculations of the different chromophores.
To test the implementation, we ran simulations on a molecular dyad, where full TDDFT nonadiabatic dynamics simulations were available. Good agreement was found.
The method was implemented in the SHARC molecular dynamics package.