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.
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.
A new paper co-authored by F. Plasser just appeared in PCCP: “Highly efficient surface hopping dynamics using a linear vibronic coupling model.” The paper shows that it is possible to perform photodynamics simulations of nonadiabatic processes, such as internal conversion and intersystem crossing, at virtually no cost.
The book chapter “General Trajectory Surface Hopping Method for Ultrafast Nonadiabatic Dynamics” written by S. Mai, F. Plasser, P. Marquetand, and L. González of the book Attosecond Molecular Dynamics edited by M. J. J. Vrakking and F. Lepine just appeared online. Download and read it if you are interested in getting an introduction into nonadiabatic surface hopping dynamics.
We just published a comprehensive and quite voluminous review paper about “Multireference Approaches for Excited States of Molecules” in Chemical Reviews. The paper covers the major methods used nowadays, such as CASSCF, multireference (MR) configuration interaction, MR perturbation theory, and MR coupled cluster. It discusses the application of semiempirical Hamiltonians as well as connections to DFT. The emerging algorithms DMRG and full-CI Quantum Monte Carlo are included as well. The theory of gradients as well as MR diagnostics and wavefunction analysis are discussed. The presented applications include a variety of cases starting from diatomics and going to complexes and dimers.
For a more detailed discussion of the paper, visit barbatti.org. For download options, see below.
You can find our new paper “Interstate vibronic coupling constants between electronic excited states for complex molecules” that recently appeared in JCP. The purpose of this paper was the development of a method that allows to determine interstate vibronic coupling constants, which are a decisive ingredient for model Hamiltonians used in quantum dynamics. Our idea was to start with a method based on wavefunction overlaps that is commonly used for trajectory dynamics simulations and adapt it for the case of quantum dynamics.
Doing computations on transition metal complexes can be very challenging. The problem is not only to find the correct computational method. But once the computation is finished, it is often difficult to even describe the results. The reason is that in the case of transition metal complexes there are many different possible types of state characters, a high density of states, and the orbitals are often not well resolved. Additional complications come into play due to spin-orbit coupling. For these reasons, we decided to take a close look at how one could make the analysis of excited states in transition metal complexes easier.
A new paper, written by S. A. Mewes as first author, appeared recently in JCTC: Benchmarking Excited-State Calculations Using Exciton Properties. In this work, we evaluated the possibility of benchmarking excited-state methods using a set of exciton analysis methods developed previously.
Felix Plasser joins the Department of Chemistry at Loughborough University on 1 February 2018 to work as Lecturer.