Jelena B. Maljković

This work presents an extension of the Belgrade ACol collisional database within the Virtual Atomic and Molecular Data Centre (VAMDC) framework to include dissociative electron attachment (DEA) processes. DEA, a low-energy electron-driven resonant mechanism leading to molecular fragmentation, is relevant in fields such as plasma science, radiation damage, nanofabrication, and EUV lithography. The ACol data model was redesigned to improve semantic clarity and flexibility by separating physical collision data from bibliographic and serialization structures. A new DataSource entity and a redefined TabulatedData–Collision relationship enable a more normalized database while preserving compatibility with the XSAMS schema through dynamic, query-time construction of hierarchical structures. The implementation is demonstrated using DEA to isoflurane, incorporating experimental data from independent studies and cataloging resulting fragment anions and energy-dependent yields. Elastic cross sections of isoflurane are included as they are immanently connected to DEA, providing an essential tool for understanding the complex DEA process. The novelty of the present implementation lies not in the first representation of DEA within VAMDC, but in its integration into a multi-process collision database based on a compact, normalized data model that separates scientific data and bibliographic provenance from the XSAMS serialization structure. The updated architecture enhances interoperability, reduces redundancy, and improves data management while maintaining compliance with VAMDC standards.

Particles from the solar wind interact with molecules from the Earth’s atmosphere creating ionized species (Marinković et al. 2025) and species with excited states. These states are responsible for Auroral formation, atmospheric chemistry and chemical species production or ozone depletion. The interactions involving excited states affect the overall energy balance and hea ting/cooling of the atmosphere (Campbell & Brunger 2018, Kirillov 2012). Long ago, the excited states of molecules have been reviewed in the three -volume series by Melvin Robin (1974, 1975, 1985). We are establishing the consortium of researchers aiming to rewrite the classic series and update data. New collection should include new laser methods, spectra in the solid (ice) phase and new theoretical calculations. These data have become so important in recent years for astronomical and space studies, whilst data for biomolecules are largely missing. We have established a webpage of MOLESs consortium (MOlecular Excited State spectroscopy) https://www.moless -spectroscopy.org/project/ The MOLESs consortium will meet annually in Belgrade. Our intention is to publish data in both e -book format and on -line with recommended data sets. Data -sets will be uploaded and curated in specified databases within VAMDC (Virtual Atomic and Molecular D ata Centre) portal https://vamdc.org/structure/databases/ (Dubernet et al. 2916, Albert et al. 2020, Vujčić et al. 2023, Srećković et al. 2025).

Isoflurane is a halogenated anaesthetic gas adopted in modern clinical practice due its efficacy and safety profile. However, its atmospheric persistence contributes to global warming potential that influences its overall environmental burden. In this study, we employed a crossed electron-molecular beam technique to investigate dissociative electron attachment (DEA) processes in order to investigate isoflurane fragmentation induced by electron impact. The DEA process results in the formation of twelve anionic fragments, including halogenated anions (Cl ⁻ and F ⁻ ), complex fluoro-chloro containing species ( e.g., [C ₂ F ₃ Cl] ⁻ , [C ₂ HFCl] ⁻ ), and oxygen-containing anions such as [CHF ₂ O] ⁻ and [CFO] ⁻ . The most intense signal corresponds to Cl ⁻ , which exhibits a sharp resonance near 0.1 eV, can be attributed to a shape resonance or due high dipole moment of isoflurane (2.47 D) to a vibrational Feshbach resonance (VFR). In contrast, F ⁻ formation is observed in a high-energy domain (4–7 eV) and proceeds via core-excited resonance. Remarkably, the [FHF] ⁻ anion was detected with unexpectedly high intensity at low energies, suggesting the occurrence of complex multi-bond dissociation and electron-induced molecular rearrangement. These findings provide important insights into the electron-induced chemistry of halogenated anaesthetics. Graphic abstract

Ionization is among the most important processes within the interstellar medium and planetary atmospheres since it defines both their physical and chemical nature. The elementary processes that lead to ionization events need to be understood and the cross sections which define the probability of different ionization pathways need to be defined in order to support the modelling of these regions. In this article we discuss the elementary processes leading to ionization events and their importance in planetary atmospheres. We focus on calculations of ionization and dissociative rate coefficients. Ionization rate coefficients derived from electron swarms as a function of the reduced electric field for planetary atmospheres in Solar system are presented as an example of ionization data required for this study. Dissociative rate coefficients for molecular hydrogen cation over a wide range of temperatures are discussed as an example of data needs. Our model is tailored for collisional reactions and may handle various atomic and molecular species, as shown for different compositions of planetary atmospheres. The model incorporates a significantly enriched set of collisional cross sections, including energy-dependent and temperature-dependent rates, as shown in calculations of dissociative rate coefficients. We also present several databases that may be used to source ionization data, with an emphasis on those developed in Belgrade.

The first week of November 2025 saw two events in Belgrade celebrating one hundred years of quantum mechanics and its impact on chemistry and molecular science. The Centennial of Quantum Theory: Progress in Atomic and Molecular Structure (CEQPAS) brought together researchers from across Europe and beyond to reflect on the scientific legacy of quantum theory and to showcase current advances in atomic and molecular spectroscopy, collision processes relevant to plasma research, chemical bonding, quantum chemistry, and the design of functional molecules, astrochemistry, the use of AI/ML for the analysis and generation of atomic and molecular data and wider applications of quantum science. Immediately after CEQPAS, a new international initiative was launched: MOLecular Excited State spectroscopy (MOLESs), whose primary goal is to develop an atlas of molecular electronic structure and excited-state spectroscopy that rigorously integrates experiment and theory. Together, CEQPAS and MOLESs align historical perspective with future capability, positioning Belgrade as a regional hub for quantum-enabled molecular science.

Absolute differential cross section for elastic electron scattering from the isoflurane molecule, both experiment and theory, at an incident electron energy of 100 eV. A significant match between the two is evident.

We report the results of the measurements and calculations of the absolute differential elastic electron scattering cross-sections (DCSs) from sevoflurane molecule (C₄H₃F₇O). The experimental absolute DCSs for elastic electron scattering were obtained for the incident electron energies from 50 eV to 300 eV, and for scattering angles from 25° to 125° using a crossed electron/target beams setup and the relative flow technique for calibration to the absolute scale. For the calculations, we have used the IAM-SCAR+I method (independent atom model (IAM) applying the screened additivity rule (SCAR) with interference terms included (I)). The molecular cross-sections were obtained from the atomic data by using the SCAR procedure, incorporating interference term corrections, by summing all the relevant atomic amplitudes, including the phase coefficients. In this approach, we obtain the molecular differential scattering cross-section (DCS), which, integrated over the scattered electron angular range, gives the integral scattering cross-section (ICS). Calculated cross-sections agree very well with experimental results, in the whole energy and angular range.