RNDr. Lukáš Félix Pašteka, PhD.

Electron correlation and relativistic effects in the excited states of radium monofluoride
Nature Communications 16, 2139 (2025)
DOI: 10.1038/s41467-025-55977-w

The radioactive molecule RaF has received a lot of attention due to its promise as a sensitive probe for searches of new physics as well as a powerful testing ground for the performance of ab initio quantum chemistry. Here, we report the spectroscopy of the 14 lowest excited electronic states of RaF compared with the state-of-the-art relativistic Fock-space coupled cluster calculations, which achieve an agreement of ≥99.64% (within  ~12 meV) with experiment for all states. The role of high-order electron correlation and quantum electrodynamics effects in the excitation energies is studied and found to be important for all states.

Solid-State Photoswitching of Hydrazones Based on Excited-State Intramolecular Proton Transfer
Journal of the American Chemical Society 147, 2421 (2025)
DOI: 10.1021/jacs.4c12510

This work describes a new type of photoswitching molecule exhibiting a rare solid-state photochromism with an unexpected red-shift of the absorption maximum. Based on our calculations, a reaction mechanism involving the excited state intramolecular proton transfer (ESIPT) has been proposed, confirmed by a slew of advanced experimental techniques, which also revealed that the observed photochromism is a surface phenomenon.

Opportunities for fundamental physics research with radioactive molecules
Reports on Progress in Physics 87, 084301 (2024)
DOI: 10.1088/1361-6633/ad1e39

This white paper discusses the untapped discovery potential for fundamental physics using radioactive molecules. A broad scientific case is made based on recent advances in atomic, molecular, nuclear, astrophysical, chemical research both from the experimental and the theoretical point of view.

Enhancing the Potential of Fused Heterocycle-Based Triarylhydrazone Photoswitches
Chemistry - A European Journal 30, e202303509 (2024)
DOI: 10.1002/chem.202303509 
(cover page) (author profiles)

A new class of photoswitches was designed featuring high thermal stability, high photoconversion rates, good addressability, and absorption closer to the visible range compared to other photoswitching molecules of this type. High-quality calculations and advanced ultrafast spectroscopy allowed the nature of the electronic transitions to be resolved, and the light was shed on the mechanism of photoisomerization and de-excitation processes.

Electroweak Nuclear Properties from Single Molecular Ions in a Penning Trap
Physical Review Letters 133, 033003 (2024)
DOI: 10.1103/PhysRevLett.133.033003

We proposed a new technique that can provide a highly sensitive route to investigate yet-to-be-explored nuclear parity-violating properties using single molecular ions. Sensitivities to these effects are predicted using ab initio calculations. These measurements will enable stringent tests of the weak interaction in stable and short-lived isotopes across the nuclear chart.

Large vibrationally induced parity violation effects in CHDBrI⁺
Chemical Communications 59, 14579 (2023)
DOI: 10.1039/D3CC03787H

Toward Detection of the Molecular Parity Violation in Chiral Ru(acac)₃ and Os(acac)₃
The Journal of Physical Chemistry Letters 13, 10011 (2022)
DOI: 10.1021/acs.jpclett.2c02434
(cover page)

In this theory-experiment investigation, helically chiral organometallic compounds are identified as candidates for next-generation experiments for detection of molecular parity violation in vibrational spectra. The parity violating effects exceed by up to 2 orders of magnitude the projected instrumental sensitivity of the ultrahigh resolution experiment under construction at the Laboratoire de Physique des Lasers in Paris.

Stereomutation of Substituted Bullvalenes
Organic Letters 23, 1157 (2021)
DOI: 10.1021/acs.orglett.0c03470
(cover page)

Boronate Ester Bullvalenes
Journal of the American Chemical Society 142, 3680 (2020)
DOI: 10.1021/jacs.9b12930

These two papers build upon our previous investigation of bullvalene (below) and extend the reraangement graph analysis and automatic PES exploration to bullvalenes containing stereogenic substituents, tethered bullvalenes, and new syntetic routes. Introducing chirality upends the usual symmetries in the reaction graphs, but also introduces new ones.

The electron affinity of astatine
Nature Communications 11, 3824 (2020)
DOI: 10.1038/s41467-020-17599-2

In this collaboration with CERN ISOLDE, the value of the electron affinity of astatine was determined in a parallel-blind study for the first time experimentally and computationally matching both results with an unprecedented level of accuracy.

Material Size Dependence on Fundamental Constants
Physical Review Letters 122, 160801 (2019)
DOI: 10.1103/PhysRevLett.122.160801
(APS Physics)

We presented a completely new pathway in detecting the variation of  fundamental constants and/or topological dark matter using laser interferometry and mass resonance. This approach is based on changes in the lattice parameters of selected solids due to the changes in the fine structure constant and proton-to-electron mass ratio, and offers sensitivity surpassing previously used techniques.

Synthesis and Analysis of Substituted Bullvalenes
Angewandte Chemie IE 57, 2570 (2018)
DOI: 10.1002/anie.201712157
(cover page)

Bullvalene is a shapeshifting molecule without a permanent structure at ambient conditions. Alongside a new two-step synthetic route, we have developed an algorithm efficiently exploring the entire energy landscape based on a rearrangement graph connecting bullvalene's 1.2 million isomers via 1.8 million transition states, and predicting the thermal populations of different substitution patterns.

Relativistic Coupled Cluster Calculations with Variational Quantum Electrodynamics Resolve the Discrepancy between Experiment and Theory Concerning the Electron Affinity and Ionization Potential of Gold
Physical Review Letters 118, 23002 (2017)
DOI: 10.1103/PhysRevLett.118.023002
(APS Physics)

Relativistic and quantum electrodynamic effects in superheavy elements
Nuclear Physics A 944, 551 (2014)
DOI: 10.1016/j.nuclphysa.2015.02.005

A review of the current status of relativistic electronic structure theory for superheavy elements and a discussion the role of quantum electrodynamic effects beyond the no-virtual-pair approximation. Changes in periodic trends due to relativistic effects are outlined and the role of the negative energy states for the electronic stability of superheavy elements beyond the critical nuclear charge is analyzed.