A5014957190- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric aerosols and clouds
- Spectroscopy and Laser Applications
- Advanced Chemical Physics Studies
- nanoparticles nucleation surface interactions
- Machine Learning in Materials Science
- Air Quality Monitoring and Forecasting
- Mass Spectrometry Techniques and Applications
- Coagulation and Flocculation Studies
- Atmospheric and Environmental Gas Dynamics
- Spectroscopy and Quantum Chemical Studies
- Advanced Chemical Sensor Technologies
- Combustion and Detonation Processes
- Air Quality and Health Impacts
- Chemical Thermodynamics and Molecular Structure
- Free Radicals and Antioxidants
- Radioactive element chemistry and processing
- Molecular Spectroscopy and Structure
- Catalytic Processes in Materials Science
- Isotope Analysis in Ecology
- Catalysis and Oxidation Reactions
- Particle Dynamics in Fluid Flows
- Optical Imaging and Spectroscopy Techniques
- Radical Photochemical Reactions
Aarhus University
2022-2025
University of Helsinki
2019-2022
University of Chemistry and Technology, Prague
2016-2020
Marymount University
2020
Charles University
2016
We studied the configurational sampling of noncovalently bonded molecular clusters relevant to atmosphere. In this article, we discuss possible approaches searching for optimal configurations and present one alternative based on systematic sampling, which seems able overcome typical problems associated with global minima multidimensional potential energy surfaces. Since atmospheric are usually held together by intermolecular bonds, also a cost-effective strategy treating hydrogen bonding...
Abstract. In atmospheric sulfuric-acid-driven particle formation, bases are able to stabilize the initial molecular clusters and thus enhance formation. The enhancing potential of a stabilizing base is affected by different factors, such as basicity abundance. Here we use weak (ammonia), medium strong (dimethylamine) very (guanidine) representative compounds, systematically investigate their ability sulfuric acid clusters. Using quantum chemistry, study proton transfer well intermolecular...
The formation of molecular clusters and secondary aerosols in the atmosphere has a significant impact on climate. Studies typically focus new particle (NPF) sulfuric acid (SA) with single base molecule (e.g., dimethylamine or ammonia). In this work, we examine combinations synergy several bases. Specifically, used computational quantum chemistry to perform configurational sampling (CS) (SA)0-4(base)0-4 five different types bases: ammonia (AM), methylamine (MA), (DMA), trimethylamine (TMA),...
Pyruvic acid is an omnipresent compound in nature and found both the gas phase particle of atmosphere as well aqueous solution hydrosphere. Despite much literature on photochemical degradation stability pyruvic different chemical environments, study simultaneous interactions between gas-phase or similar carboxylic acids with water ions not well-understood. Here, we present a microhydrated molecular clusters containing structurally analogous lactic acid, propionic 2,2-dihydroxypropanoic by...
High molecular weight "ROOR'" dimers, likely formed in the gas phase through self- and cross-reactions of complex peroxy radicals (RO2), have been suggested to play a key role forming ultrafine aerosol particles atmosphere. However, molecular-level reaction mechanism producing these dimers remains unknown. Using multireference quantum chemical methods, we explore one potentially competitive pathway for ROOR' production, involving initial formation triplet alkoxy radical (RO) pairs, followed...
We tested the influence of various parameters on new particle formation rate predicted for sulfuric acid–ammonia system using quantum chemistry and cluster distribution dynamics simulations, in our case, Atmospheric Cluster Dynamics Code (ACDC). found that consistent consideration rotational symmetry number monomers (sulfuric acid ammonia molecules, bisulfate ammonium ions) leads to a significant rise rate, whereas inclusion clusters only changes results slightly, conditions where charged...
Ions enhance the formation rate of atmospheric aerosol particles, which play an important role in Earth’s radiative balance. Ion-induced nucleation involves stepwise accretion neutral monomers onto a molecular cluster containing ion, helps to stabilize against evaporation. Although theoretical frameworks exist calculate collision coefficients between molecules and ions, they need be experimentally confirmed, ideally under atmospherically relevant conditions around 1000 ion pairs cm−3. Here,...
Nanometer-scale clusters form from vapor-phase precursors and can subsequently grow into nanoparticles during atmospheric nucleation events. A particularly interesting set of relevant to is hybrid iodine pentoxide-iodic acid the (I2O5) x(HIO3) y as these have been observed in coastal region events anomalously high concentrations. To better understand their properties, we utilized ion mobility-mass spectrometry probe structures cluster anions y(IOα)- ( x = 0-7, 0-1, α 1-3), similar those We...
Organic peroxy radicals (RO2) are key intermediates in the chemistry of atmosphere. One main sink reactions RO2 is recombination reaction + R'O2, which has three channels (all with O2 as a coproduct): (1) R-H═O R'OH, (2) RO R'O, and (3) ROOR'. The R'O "alkoxy" channel promotes radical oxidant recycling, while ROOR' "dimer" leads to low-volatility products relevant aerosol processes. only recently been discovered play role gas phase. Recent computational studies indicate that all these first...
Quantum chemical studies of the formation and growth atmospheric molecular clusters are important for understanding aerosol particle formation. However, search lowest free-energy cluster configuration is extremely time consuming. This makes high-level benchmark data sets valuable in quest global minimum as it allows identification cost-efficient computational methodologies, well development machine learning (ML) models. Herein, we present a highly versatile quantum set comprising total 11...
Quantum chemical (QC) calculations can yield direct insight into an atmospheric cluster formation mechanism and rates. However, such are extremely computationally demanding as more than millions of configurations might exist need to be computed. We present efficient approach produce high quality QC data sets for applications in studies how train accurate quantum machine learning model on the generated data. Using two-component sulfuric acid─water system a proof concept, we demonstrate that...
Studying large atmospheric molecular clusters is needed to understand the transition between and aerosol particles. In this work, we studied (SA)n(AM)n with n up 30 (SA)m(AM)m±2 clusters, m = 6-20. The cluster configurations are sampled using ABCluster program, geometries thermochemical parameters calculated GFN1-xTB. binding energies B97-3c. We find that addition of sulfuric acid preferred ammonia. free were found have uncertainties, which could potentially be attributed errors in applied...
Atmospheric molecular cluster formation is the first stage toward aerosol particle formation. Despite intensive progress in recent years, relative role of different vapors and mechanisms for forming clusters still not well-understood. Quantum chemical (QC) methods can give insight into thereby yield information about potentially relevant compounds. Here, we summarize QC literature on clustering involving species such as sulfuric acid, methanesulfonic nitric acid. The importance iodine iodous...
The nucleation process leading to the formation of new atmospheric particles plays a crucial role in aerosol research. Quantum chemical (QC) calculations can be used model early stages formation, where vapor molecules interact and form stable molecular clusters. However, QC heavily depend on chosen computational method, when dealing with large systems, striking balance between accuracy cost becomes essential. We benchmarked binding energies structures found B97-3c method good compromise for...
Reparameterization of GFN1-xTB for atmospheric molecular clusters leads to a massive decrease in energy errors and deviation.
Abstract. Sulfuric acid and dimethylamine vapours in the atmosphere can form molecular clusters, which participate new particle formation events. In this work, we have produced, measured, identified clusters of sulfuric using an electrospray ionizer coupled with a planar-differential mobility analyser, connected to atmospheric pressure interface time-of-flight mass spectrometer (ESI–DMA–APi-TOF MS). This set-up is suitable for evaluating extent fragmentation charged inside instrument. We...
Formation and growth of atmospheric molecular clusters into aerosol particles impact the global climate contribute to high uncertainty in modern models. Cluster formation is usually studied using quantum chemical methods, which quickly becomes computationally expensive when system sizes grow. In this work, we present a large database ∼250k relevant cluster structures, can be applied for developing machine learning (ML) The used train ML model kernel ridge regression (KRR) with FCHL19...
Multicomponent atmospheric molecular clusters, typically comprising a combination of acids and bases, play pivotal role in our climate system contribute to the perplexing uncertainties embedded modern models. Our understanding cluster formation is limited by lack studies on complex mixed-acid-mixed-base systems. Here, we investigate multicomponent clusters consisting mixtures several acid base molecules: sulfuric (SA), methanesulfonic (MSA), nitric (NA), formic (FA), along with methylamine...
Computational modeling of atmospheric molecular clusters requires a comprehensive understanding their complex configurational spaces, interaction patterns, stabilities against fragmentation, and even dynamic behaviors. To address these needs, we introduce the Jammy Key framework, collection automated scripts that facilitate streamline cluster workflows. handles file manipulations between varieties integrated third-party programs. The framework is divided into three main functionalities: (1)...
Abstract. When simulating new particle formation rates, collisions in the system are approximated as hard spheres without long-range interactions. This simplification may lead to an underestimation of actual rate. In this study, we employ semi-empirical molecular dynamics (SEMD) at GFN1-xTB level theory probe sticking process monomers sulfuric acid (SA), methanesulfonic (MSA), nitric (NA), formic (FA), ammonia (AM), methylamine (MA), dimethylamine (DMA), and trimethylamine (TMA) onto freshly...
In the initial stages of atmospheric aerosol particle formation, molecules collide and stick together, forming dimers small clusters. This is an inherently dynamic process. Molecular dynamics (MD) simulations allow us to model behavior these collision systems. MD simulations, trajectory a system divided into discrete timesteps, with forces on nuclei computed at each step propagate system. Traditionally, are calculated using classical force fields, which highly efficient for large systems...
Molecular dynamics (MD) simulations of systems with many atoms are often constrained by computational limitations, requiring either short simulation times or the use force-field methods. Recently, we demonstrated that machine-learning (ML) potentials can be trained on small molecular systems, such as clusters, computationally explorable via accurate quantum chemistry These ML subsequently used to model larger while maintaining same energy-per-atom and force-per-atom accuracy. This allows us...