The activities of the research group are aimed at doing leading-edge basic research in the fields of theoretical and computational chemistry, in particular molecular quantum chemistry, computational molecular spectroscopy, first-principles thermochemistry, and reaction kinetics. Regular utilization and extension of algorithms from interdisciplinary areas, such as mathematical statistics, informatics, and information technology, during the investigation of complex chemical systems, and elevation of existing knowledge into new heights by bridging several of these areas is expected. The group develops generally applicable methods and techniques, with special emphasis on related high-level computer codes, which help to understand our wider natural environment (e.g., combustion systems, star formation, and exoplanets), as well as to protect the quality of life (e.g., via an improved scientific understanding of the greenhouse effect on earth and research and development related to climate changes). Establishment of modern, active chemical databases is another core activity of the group. Some of the databases are built upon data mining using novel methods of discrete mathematics, especially noteworthy are those related to high-resolution molecular spectroscopy (spectroscopic networks). The databases include a searchable bibliographical chemical kinetics data collection, a database of high temperature gas kinetics elementary reactions with information on the available experimental data and an assessment of the uncertainty of the rate parameters. Another database includes raw experimental data in the field of combustion chemistry. These specialized databases are cross referenced with each other and with the spectroscopic and thermodynamics databases. All the methods, codes, and databases developed are made available to the general public for the benefit of interested scientists and engineers.
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Prof. Dr. Attila G. Császár Office: 539 Phone: 1629 Email: attila.csaszar at ttk.elte.hu Website: link |
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Dr. Tibor Furtenbacher Office: 538 Phone: -- Email: furtibu at gmail.com Website: link |
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Dr. Péter Árendás Office: -- Phone: -- Email: mreti88 at gmail.com Website: -- |
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Dr. Csaba Fábri Office: 5.116 Phone: 6505 Email: fabrics2 at gmail.com Website: link |
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Dr. Tamás Szidarovszky Office: 5.116 Phone: 6505 Email: tamas821 at gmail.com Website: link |
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Dr. Roland Tóbiás Office: 5.116 Phone: 6505 Email: tobiroli at gmail.com Website: -- |
Some 30 years ago, Richards [1], and later Schaefer [2,3],
categorized the development of computational quantum chemistry into three ages,
which was accepted by the research community right away.
In the first age of quantum chemistry, the crude computations based on quantum mechanics
were able to provide only qualitative explanations of relevant experiments,
and the agreement between theory and experiment was within let’s say an order of magnitude.
This period lasted up until about the 1950s.
In the second age, the tools of quantum chemistry were developed at a very fast pace.
The availability of digital computers greatly influenced the development of the field
and theory started to offer not only insight into the principles behind the measured
properties but also semi-quantitative results, able to help or even shape measurements.
Then, the year 1978 was chosen as the start of the mature,
third age of quantum chemistry, whereby theory has become able to make
quantitative predictions and thus challenge (or even overrule) experiments
and/or their interpretations.
It has to be pointed out, however, that within this scheme quantum chemistry was
basically identified as electronic structure theory and thus only the development
of electronic structure theory was considered when the successes of
quantum chemistry were discussed.
Of course, the other important branch of quantum chemistry besides electronic structure theory
deals with the motion of the nuclei within the molecule, probed usually
through high-resolution molecular spectroscopy or by following chemical reactions [4].
While electronic structure theory has been quite successful in yielding quantities which
can be related, usually at an elementary level, to experimental observables,
truly quantitative agreement with experiments can only be expected if the motions
of the nuclei are also considered.
It is hoped in this context that we are in, or at least entering,
the fourth age of quantum chemistry [5], whereby quantum chemistry,
now inclusive of both electronic structure and nuclear motion theories,
would quantitatively bridge the gap between ‘effective’, experimental observables and
‘equilibrium’ computed quantities at arbitrary temperatures of interest and provides results
in full quantitative agreement with the best measurements,
help to overrule incorrect measurements, and substitute experiments when
they are too expensive or otherwise impossible to perform.
We may even say tentatively that the fourth age of quantum chemistry started
in one subfield of nuclear motion theory, in molecular spectroscopy, when we could first
demonstrate convincingly [6] that “third-age” electronic-structure techniques can be used
to get spectroscopic accuracy, defined as 1 cm–1 on average,
from purely first-principles computations for the complete experimentally measured spectra of all the
isotopologues of a polyatomic and polyelectronic molecule, water,
via variational nuclear motion computations.
Related publications:
(1) Richards, G. Nature 1979, 278, 507.
(2) Schaefer, H. F. Chimia 1989, 43, 1.
(3) Schaefer, H. F. Science 1986, 231, 1100.
(4) A. G. Császár, G. Czakó, T. Furtenbacher, and E. Mátyus, An Active Database Approach to Complete Rotational-Vibrational Spectra of Small Molecules, Ann. Rep. Comp. Chem. 2007, 3, 155-176.
(5) A. G. Császár, C. Fábri, T. Szidarovszky, E. Mátyus, T. Furtenbacher, and G. Czakó, Fourth Age of Quantum Chemistry: Molecules in Motion, Phys. Chem. Chem. Phys. 2012, 14(3), 1085-1106.
(6) O. L. Polyansky, A. G. Császár, S. V. Shirin, N. F. Zobov, P. Barletta, J. Tennyson, D. W. Schwenke, and P. J. Knowles, High-Accuracy Ab Initio Rotation-Vibration Transitions for Water, Science 2003, 299, 539-542.
Hugh Ross, in his famous book The Fingerprint of God (Whitaker House, 1989),
summarized several important questions related to modern science:
(1) Is our universe finite or infinite in size and content?
(2) Has this universe been here forever or did it have a beginning?
(3) Was the universe created?
(4) If the universe was not created, how did it get here?
(5) If the universe was created, how was this creation accomplished,
and what can we learn about the agent and events of creation?
(6) Who or what governs the laws and constants of physics?
(7) Are such laws the products of chance or have they been designed?
(8) How do the laws and constants of physics relate to the support and development of life?
(9) Is there any knowable existence beyond the apparently observed dimensions of the universe?
(10) Do we expect the universe to expand forever, or is a period of contraction to be followed
by a big crunch?
While answers to some of these questions lie outside of the territory of chemistry,
chemistry should help answering some of the last questions where molecules play a decisive role.
It is generally accepted that almost all present-day knowledge about the structure and properties
of molecules comes via studies of their spectra.
Although laboratory measurements are usually considered to be the prime sources
for the relevant information, there are a number of occasions where theory has played,
and will continue to play, a central role in the understanding of properties of molecules and their spectra.
Cutting-edge studies in spectroscopy help to answer more mandane questions than those raised
above but these questions and answers are still highly interesting to those studying nature.
Astronomical environments, such as those found in interstellar media,
are very different from those on Earth.
This dissimilarity leads to a fundamentally different chemistry and to the production
of species that can be hard to create in the laboratory.
Theory can play an important role in predicting the main features of the spectra
of such species or looking for possible spectral matches in other solar systems
and in the atmospheres of exoplanets.
The detailed understanding of the chemistry taking place in astronomical environments
is central to understand a couple of less grand but still important questions:
(1) How did the solar systems form?
(2) Will the understanding of chemistry on earth help to understand chemistry in
diverse astronomical objects?
(3) How did the building blocks of life form on earth and outside of earth?
(4) How did life begin on earth?
(5) Would understanding of the origin of life on earth help to understand the origin
of life and its building blocks in other solar systems and on exoplanets?
Theoretical high-resolution molecular spectroscopy offers important contributions
toward answering at least parts of these questions.
Another important point is that even when laboratory spectra have been
recorded for a particular species, this data may only be partial.
One such situation, which is particularly common for unstable or reactive species,
is that wavelengths can be measured to high accuracy but there is no or extremely
limited information on transition probabilities and line strengths.
To understand these one needs to compute potential energy (PES)
and property (like the dipole moment surface, DMS) hypersurfaces [1,2]
which can be obtained with modern techniques of electronic structure theory.
Computing accurate and global PESs and DMSs is still a considerable challenge for polyatomic systems.
It must be realized that many modelling applications are particularly demanding on spectroscopic data.
For example, to model the role of triatomic species,
such as H2O [3] or [H,C,N], which are important components of O-rich and C-rich cool stars, respectively,
may require up to a billion vibration-rotation transitions.
The laboratory measurement and analysis of a dataset of transitions of this size
is completely impractical.
Computational molecular spectroscopy, with its fourth-age quantum chemical techniques [4],
come to the rescue and allows the straightforward determination of huge molecular linelists.
Related publications:
[1] A. G. Császár, W. D. Allen, Y. Yamaguchi, and H. F. Schaefer III,
Ab Initio Determination of Accurate Potential Energy Hypersurfaces for the Ground Electronic States
of Molecules, in Computational Molecular Spectroscopy, 2000, eds. P. Jensen and P. R. Bunker,
Wiley: New York.
[2] A. G. Császár, G. Tarczay, M. L. Leininger, O. L. Polyansky, J. Tennyson, and W. D. Allen,
Dream or Reality: Complete Basis Set Full Configuration Interaction Potential Energy Hypersurfaces,
in Spectroscopy from Space, edited by J. Demaison, K. Sarka, and E. A. Cohen (Kluwer, Dordrecht, 2001),
pp. 317-339.
[3] O. L. Polyansky, A. G. Császár, S. V. Shirin, N. F. Zobov, P. Barletta, J. Tennyson,
D. W. Schwenke, and P. J. Knowles, High-Accuracy Ab Initio Rotation-Vibration Transitions of Water,
Science 2003, 299, 539-542.
[4] A. G. Császár, C. Fábri, T. Szidarovszky, E. Mátyus, T. Furtenbacher, and G. Czakó,
Fourth Age of Quantum Chemistry: Molecules in Motion, Phys. Chem. Chem. Phys. 2012, 14(3), 1085-1106.
Detailed reaction mechanisms may contain from several hundred to several tens of
thousands of reaction steps. Such detailed reaction mechanisms are widely used
in science and engineering for the description of combustion systems, atmospheric chemistry,
process engineering, and even biological processes. The reaction mechanisms
contain a large number of reaction rate parameters, and they may also contain many
spectroscopic and thermodynamic data.
Studies in reaction kinetics in the research group are centered around the
investigation of uncertainty [1, 2]. Experimental data are collected from
the literature and the uncertainty of these data is assessed. Such
experimental data include the results of direct measurements, when the rate
coefficients are measured directly, and indirect measurements.
In combustion systems such indirect measurements include determinations of
laminar flame velocity and ignition delay time. Fitting reaction kinetic and
thermodynamic parameters of detailed reaction mechanisms to direct and
indirect experimental data allows a new, more accurate determination of
important physico-chemical parameters [3, 4]. Another important result of
such parameter fitting studies is the determination of the correlated
uncertainty of the parameters of these mechanisms.
Successful application of detailed reaction mechanisms depends on
the reliability of the simulation results, which can be quantified by their
uncertainty. The methods of uncertainty analysis [3, 5] allow the
calculation of the uncertainty of model results based on the uncertainty of
model parameters. The obtained uncertainty information is important for all
users of detailed reaction mechanisms.
Related publications:
[1] T. Turányi, T. Nagy, I. Gy. Zsély, M. Cserháti, T. Varga, B.T. Szabó,
I. Sedyó, P. T. Kiss, A. Zempléni, H. J. Curran, Determination of rate
parameters based on both direct and indirect measurements,
Int.J.Chem.Kinet., 2012, 44, 284-302.
[2] T. Nagy, T. Turányi, Uncertainty of Arrhenius parameters, Int. J. Chem.
Kinet., 2011, 43, 359-378.
[3] A.S. Tomlin, T. Turányi, Investigation and improvement of reaction
mechanisms using sensitivity analysis and optimization, Chapter 16 in:
Development of detailed chemical kinetic models for cleaner combustion,
editors: F. Battin-Leclerc, E. Blurock, J. Simmie, pp. 411-445, Springer,
Heidelberg, 2013
[4] I. Gy. Zsély, T. Varga, T. Nagy, M. Cserháti, T. Turányi, S. Peukert, M.
Braun-Unkhoff, C. Naumann, U. Riedel, Determination of rate parameters of
cyclohexane and 1-hexene decomposition reactions, Energy, 2012, 43 , 85-93.
[5] J. Zádor, I. Gy. Zsély, T. Turányi, M. Ratto, S. Tarantola, A. Saltelli,
Local and global uncertainty analyses of a methane flame model, J. Phys.
Chem. A, 2005, 109, 9795-9807.
NEAT [1], standing for
„network of computed reaction anthalpies leading to atom-based thermochemistry”,
is a simple and fast, weighted, linear least-squares refinement protocol and code
for inverting the information contained in a network of quantum chemically computed 0 K
reaction enthalpies.
This inversion yields internally consistent 0 K enthalpies of formation for
the species of the network.
The refinement takes advantage of the fact that the accuracy of computed enthalpies
depends strongly on the quantum-chemical protocol employed for their determination.
Different protocols suffer from different sources of error;
thus, the reaction enthalpies computed by them have “random” residual errors.
Since it is much more natural for quantum-chemical energy and enthalpy results,
including reaction enthalpies, to be based on the electronic ground states of
the atoms and not on the historically preferred elemental states,
and since these two possible protocols can be converted into each other straightforwardly,
it is proposed that first-principles thermochemistry should employ the
ground electronic states of atoms.
In this scheme, called atom-based thermochemistry (AT),
the enthalpy of formation of a gaseous compound corresponds simply to the
total atomization energy of the species;
it is always positive, and it reflects the bonding strength within the molecule.
The inversion protocol developed and based on AT is termed NEAT, which represents
the fact that the protocol proceeds from a network of computed reaction enthalpies
toward atom-based thermochemistry, most directly to atom-based enthalpies of formation.
First-principles thermochemistry relies on advanced techniques of electronic structure theory
to compute accurate electronic thermochemical quantities,
while for the determination of temperature-dependent, effective quantities one needs
the techniques of nuclear motion theory.
One of the key questions in electronic structure theory concerns the accuracy of the
computed molecular quantities, including relative energies.
The composite focal-point analysis (FPA) approach developed some two decades ago by us [2-5]
provides a clean way to determine the uncertainties of computed relative energies.
Another important area of the application of quantum chemistry in thermochemistry concerns the determination of accurate
partition functions and related thermochemical data of small(er) molecules with well-defined uncertainties. The traditional
approaches rely either on simple model assumptions or on effective Hamiltonians fitted to experimental data. Thus, they give
poor results with unknown uncertainties especially at higher temperatures. Based on the joint use of the in-house MARVEL protocol
and nuclear motion computations, the explicit summation technique based on accurate rovibrational energy levels with known
uncertainties offers a clean and accurate way to determine thermochemical quantities over a wide temperature range (T lt 6000 K)
which could be used in many scientific and engineering applications.
Related publications:
[1] A. G. Császár and T. Furtenbacher,
From a Network of Computed Reaction Enthalpies to Atom-Based Thermochemistry (NEAT),
Chem. Eur. J. 2010, 16(16), 4826-4835.
[2] W. D. Allen, A. L. L. East, and A. G. Császár,
Structures and Conformations of Non-Rigid Molecules, edited by J. Laane, M. Dakkouri,
B. van der Veken and H. Oberhammer (Kluwer, Dordrecht, 1993), pp. 343-373.
[3] A. G. Császár, W. D. Allen, and H. F. Schaefer, III,
In Pursuit of the Ab Initio Limit for Conformational Energy Prototypes, J. Chem. Phys. 1998,
108, 9751-9764.
[4] A. G. Császár, W. D. Allen, Y. Yamaguchi, and H. F. Schaefer III,
Ab Initio Determination of Accurate Potential Energy Hypersurfaces for the
Ground Electronic States of Molecules, in Computational Molecular Spectroscopy, 2000,
eds. P. Jensen and P. R. Bunker, Wiley: New York.
[5] A. G. Császár, G. Tarczay, M. L. Leininger, O. L. Polyansky, J. Tennyson, and W. D. Allen,
Dream or Reality: Complete Basis Set Full Configuration Interaction Potential Energy Hypersurfaces,
in Spectroscopy from Space, edited by J. Demaison, K. Sarka, and E. A. Cohen
(Kluwer, Dordrecht, 2001), pp. 317-339.
A research article entitled “Coupling polyatomic molecules to lossy nanocavities: Lindblad vs Schrödinger description” (https://doi.org/10.1063/5.0205048) has been chosen to be promoted as an Editor’s Pick in the Journal of Chemical Physics. The article compares quantum-dynamical descriptions based on the time-dependent Schrödinger and Lindblad master equations for a molecule coupled to a lossy nanocavity.
A research article entitled “Impact of Cavity on Molecular Ionization Spectra” (https://doi.org/10.1021/acs.jpclett.4c00247) was published in the Journal of Physical Chemistry Letters, a leading-edge research journal of the Americal Chemical Society. The article presents the very first investigation of molecular ionization spectra in a cavity environment.
A Focused Review titled “Classical and quantum light-induced non-adiabaticity in molecular systems” (https://doi.org/10.1116/5.0191522) was published in AVS Quantum Science, a journal of the American Institute of Physics. The Editors have chosen to promote our work as a Feature Article.
Research.com, a leading academic platform for researchers, has released the 2023 Edition of the Ranking of Best Scientists in the field of Chemistry. Attila G. Császár has ranked #2 in Hungary and #4504 in the world. He has also been recognized with the Chemistry Leader Award for 2023. The ranking is based on D-index (Discipline H-index) metric, which only includes papers and citation values for an examined discipline.
The full ranking for Hungary is available here.
The full world ranking is available here.
Our article titled “Topological aspects of cavity-induced degeneracies in polyatomic molecules” (https://doi.org/10.1002/qua.26750) is among the most downloaded papers in International Journal of Quantum Chemistry.
A research article entitled “Radiative emission of polaritons controlled by light-induced geometric phase” (https://doi.org/10.1039/D2CC04222C) was published in Chemical Communications, a journal of the Royal Society of Chemistry publishing results of outstanding urgency and significance across the chemical sciences. Our communication highlights the impact of light-induced geometric phase effects on ultrafast radiative emission from the lower molecular polaritonic state.
A research article entitled “Probing Light-Induced Conical Intersections by Monitoring Multidimensional Polaritonic Surfaces” (https://doi.org/10.1021/acs.jpclett.1c03465) was published in the Journal of Physical Chemistry Letters, a leading-edge research journal of the Americal Chemical Society. The article demonstrates that the time-resolved ultrafast radiative emission of an optical cavity can be utilized to follow both nuclear wavepacket dynamics on, and nonadiabatic population transfer between, molecular polaritonic surfaces.
An Edge Article entitled “Born–Oppenheimer approximation in optical cavities: from success to breakdown” (https://doi.org/10.1039/D0SC05164K) was published in Chemical Science, a flagship journal of the Royal Society of Chemistry. The paper became part of the Editor’s Choice – Graeme Day and 2020 Chemical Science HOT Article Collection themed collections. Our work takes an important step towards a better understanding of the Born-Oppenheimer approximation applied to molecular polaritonic states.
A research article authored by members of KKRK was featured on the front cover of the Journal of Physical and Chemical Reference Data. The paper gives an update to the W2020 database of validated experimental transitions and accurate empirical energy levels of water isotopologues. The W2020 database now contains almost all of the transitions required for a successful spectroscopic modeling of atmospheric water vapor.
A research article co-authored by three members of KKRK has been recognized by the Editors of Physical Chemistry Chemical Physics (PCCP) as a 2020 Hot PCCP article. The perspective-style article titled "Rotational–vibrational resonance states" presents a number of different theoretical approaches and computational methods to describe the metastable rovibrational resonance states of polyatomic molecules.
Tamás Szidarovszky, a member of KKRK received the Academic Youth Prize from the leaders of the Hungarian Academy of Sciences. The Academic Youth Prize was founded by the Secretary General of the Hungarian Academy of Sciences in 1972 to encourage the professional work of young researchers and to acknowledge outstanding scientific achievements.
As a result of a joint research project between KKRK and scientists at the University of Cologne, a paper titled "Infrared Signatures of the HHen+ and DHen+ (n = 3–6) Complexes" was published in the prestigious journal of JPCL. The published article contains the first experimental characterization of vibrational fundamentals of the He–X+–He (X = H, D) chromophore of the in situ prepared HHen+ and DHen+ (n = 3–6) complexes. The experimental results are supported and verified by first-principles quantum-chemical computations.
A research article co-authored by two members of KKRK (Tamás Szidarovszky and Attila G. Császár) has been included in the virtual issue of the American Chemical Society (ACS) titled "Strong Field Chemistry". The collection was published jointly by The Journal of Physical Chemistry A and The Journal of Physical Chemistry Letters to highlight the progress and to show the future direction of this important field. The selected article co-authored by KKRK members contains the theoretical framework for computing the absorption and stimulated emission spectrum of molecules dressed by laser light, and shows how the presence of a so-called light-induced conical intersection affects the rovibronic spectrum.
Tamás Szidarovszky, a member of KKRK was invited to give a presentation at the International Symposium of Ultrafast and Intense Laser Science 2019 held in Kushiro, Japan. He gave a talk about the theoretical simulations on the strong-field Fourier transform spectroscopy of H2O+ and D2O+ cations, which were carried out under a joint project between KKRK and the group of Professor Kaoru Yamanouchi at The University of Tokyo.
Tamás Szidarovszky, a researcher of KKRK has received the "Excellent Researcher of the Institute of Chemistry, Eötvös Loránd University" award. The annual prize is awarded to a scientist of the institute, who demonstrated outstanding scientific results in the preceding year. The two publications of KKRK forming the basis of this year's award are titled "Direct signatures of light-induced conical intersections on the field-dressed spectrum of Na2" and "Conical intersections induced by quantum light: field-dressed spectra from the weak to the ultrastrong coupling regimes".
Tamás Szidarovszky, a researcher of KKRK has reached the finals of FameLab Hungary. FameLab is a global science communication competition, in which participants have three minutes to present a scientific topic to the judges and audience. Tamás's talk was on the physics of drums, the presentation can be seen here (starting at around 54:00).
A research article co-authored by two members of KKRK has been chosen to be promoted as an Editor’s Pick in the Journal of Chemical Physics. The article titled “Controlling tunneling in ammonia isotopomers” reports the first full-dimensional rotational-vibrational investigation of the coherent inhibition and enhancement of tunneling in ammonia isotopomers by laser fields.
As a result of a joint research project between KKRK and scientists at the University of Debrecen, a paper titled "Conical intersections induced by quantum light: field-dressed spectra from the weak to the ultrastrong coupling regimes" was published in the prestigious journal of JPCL. The published article contains the theoretical framework for computing the absorption and stimulated emission spectrum of molecules dressed by the quantized radiation field of a microscopic cavity.
A research article co-authored by members of KKRK is among the top 10 most read papers of The Journal of Physical Chemistry Reference Data in 2018. The paper demonstrates state-of-the-art determination of thermochemical functions for heavy water and its substituent isotopologues. The accurate data published can be used to predict the gas-phase thermodynamic properties of heavy water at very low, or elevated temperatures.
A member of KKRK was invited to give a talk at the 16th Central European Symposium on Theoretical Chemistry (CESTC2018) held in Srni (Czeck Republic) between the 9th and 12th of September 2018. The topic of the lecture was the theoretical description and computation of the rovibronic spectrum of so-called light-dressed molecules, which are formed when molecules interact with long laser pulses or the radiation field of microscopic optical or plasmonic cavities. Investigating the spectrum of light-dressed molecules reveals much of the physical nature of these systems and provides valuable spectroscopic data on the molecules not observable in classical gas-phase spectroscopy.
Two members of KKRK (Csaba Fábri and Attila G. Császár) have published a Communication titled Vibrational quantum graphs and their application to the quantum dynamics of CH5+ in Physical Chemistry Chemical Physics. The paper describes the very first application of the quantum-graph model to the vibrational quantum dynamics of molecules and demonstrates that the simple and intuitive quantum-graph model is able to decipher the complex and unique vibrational quantum dynamics of CH5+. Csaba Fábri presented a poster (AMOC 2018), an invited talk (3rd COST MOLIM General Meeting) and a contributed talk (Internal Symposium on Molecular Spectroscopy) about the topic.
On June 27, 2018, Prof. Bill Poirier (Texas Tech University, Lubbock, TX), a previous visitor to the KKRK group, received a two-year supplement for his existing NSF CHE 1665370 grant, entitled Massively Parallel Quantum Dynamics: Computing many accurate quantum states for real molecular applications. The supplement is aimed at establishing a strong collaboration between Poirier, Jonathan Tennyson (UCL, London), and Attila G. Császár and the KKRK team. The joint effort is directed toward enabling algorithmic improvements, joint code development and outreach activities, and the significant extension of the computational quantum dynamics user base. The collaboration will begin to explore the development of a common syntax for quantum dynamical rovibrational spectroscopy computations for the benefit of the various user communities currently impacted by the well-established quantum dynamics codes of the collaborators.
A member of KKRK was invited to give a lecture at the COST Training School "Bridging experiment and theory in precision spectroscopy" held in Toruń (Poland) between the 26th and 30th of June 2018. The topic of the lecture was the theoretical description and computation of metastable quantum states (also called quasibound or resonance states), which play a fundamental role in a large variety of chemical and physical processes.
A research article co-authored by two members of KKRK has been recognized in the Web of Science core collection both as a "Hot Paper" and a "Highly Cited Paper" (a hot paper represents a top 0.1% paper in the research field). The article titled "The HITRAN2016 molecular spectroscopic database" describes the contents of the 2016 edition of the canonical HITRAN molecular spectroscopic information system, which is one of the most popular and widely used databases of the scientific and engineering communities. The compilation can be accessed at www.hitran.org.
Tamás Szidarovszky, a member of KKRK became a co-chair of the International Symposium of Ultrafast and Intense Laser Science 2018. The conference is to be held between October 14th and 19th, 2018, in Visegrád, Hungary.
As a result of a joint research project between KKRK and scientists at the University of Debrecen, a paper titled "Direct signatures of light-induced conical intersections on the field-dressed spectrum of Na2" was published in the prestigious journal of JPCL. The published article contains the theoretical framework for computing the absorption and stimulated emission spectrum of molecules dressed by laser light, and shows how the presence of a so-called light-induced conical intersection effects the rovibronic spectrum.
Tamás Szidarovszky, a member of KKRK has been awarded a Certificate of Outstanding Contribution in Reviewing by the Karbala International Journal of Modern Science.
Professor Kaoru Yamanouchi from The University of Tokyo will visit our laboratory in April this year. During his visit Professor Yamanouchi will discuss with us ongoing as well as potential future collaborations between KKRK and the Yamanouchi Laboratory. We are looking forward to welcoming you in Hungary Professor Yamanouchi!
A research article co-authored by members of KKRK was selected as Editor's choice at The Journal of Physical Chemistry Reference Data. The paper demonstrates state-of-the-art determination of thermochemical fucntions for heavy water and its substituent isotopologues. The accurate data published can be used to predict the gas-phase thermodynamic properties of heavy water at very low, or elevated temperatures.
Researchers of KKRK are organizing the third AMOC (Anharmonicity in Medium-Sized Molecules and Clusters) conference this year, to be held in Budapest between April 16-19. The first two meetings were held in Paris and Madrid in 2012 and 2015, respectively. The AMOC conferences are designed to facilitate a deep and critical discussion of all topics related to anharmonicity in a broad sense in a friendly and welcoming atmosphere.
The 3rd General Meeting of our COST action CM1405, MOLIM will take place in Budapest between April 19 and 21, 2018. Following the well-established traditions of MOLIM, with the two previous meetings taking place in Paris (August 27 - 29, 2015) and Dubrovnik (October 10-12, 2016), there will be talks given by members of the four Working Groups and the three Task Forces of MOLIM as well as by young scientists who made significant contributions to the successes of our Action.
Researchers of KKRK participated in a joint international work contributing to the HITRAN2016 Special Issue of the Journal of Quantitative Spectroscopy and Radiative Transfer. The publication presents total internal partition functions for 166 isotopologues of 51 molecules important in planetary atmospheres.
Professor Attila Császár gave an invited talk at the 88th Asia-Pacific Conference of Theoretical and Computational Chemistry (December 15-17, 2017, Mumbai, India) with the title "Molecules in Motion".
Csaba Fábri, a member of KKRK completed a Short Term Scientific Mission (STSM) at ETH Zürich between 2017-10-26 and 2017-11-09. STSMs aim to promote exchange (mobility) and allow scientists, especially Early Career Investigators, to visit an active research group in another MOLIM-participating country in order to foster collaboration, share knowledge, learn a new technique, and undertake research of common interest. The title of the STSM work plan of Csaba Fábri is "Time-dependent quantum dynamics of achiral and chiral molecules under coherent irradiation".
Professor Attila Császár gave an invited talk at the 25th International Conference on Current Trends in Computational Chemistry (November 9-11, 2017, Jackson, MS, USA) with the title "Molecules in Motion".
Tamás Szidarovszky, a member of KKRK was invited to be a discussion leader at the International Symposium of Ultrafast and Intense Laser Science 2017. He gave an introductory talk on the topic of molecules in intense laser fields, and presented a poster with the title "LIMAO: Cross-platform software for simulating laser-induced alignment and orientation dynamics of linear-, symmetric- and asymmetric tops" representing a joint project between KKRK and the group of Professor Kaoru Yamanouchi at The University of Tokyo.
A research article co-authored by members of KKRK was selected as Editor's choice in the October 7, 2017 issue of The Journal of Chemical Physics. The paper demonstrates a state-of-the-art approach for describing and understanding the nuclear motion of highly flexible, so-called astructural polyatomic molecules. Numerical results are presented for the CH5+ cation.
Professor Attila Császár gave an invited talk at the MOLIM Workshop on Intermolecular Interactions (October 2-4, 2017, Santiago de Compostela, Spain) with the title "The Fairyland of Molecular Complexes".
Professor Attila Császár gave an invited talk at the 11th Triennial Congress of the World Association of Theoretical and Computational Chemists (August 27-Sept. 1, Munich, Germany) with the title "Astructural Molecules".
Professor Attila Császár gave an invited talk at the Telluride Workshop on Spectroscopy and Dynamics of Coupled Anharmonic Vibrations of Floppy Molecular Systems (July 17-21, 2017, Telluride, CO, USA) with the title "The Chemical Fairyland of Loosely Bound Molecules".
Csaba Fábri and Tamás Szidarovszky, two researchers of KKRK were awarded with the prestigious postdoctoral grant of the National Research, Development and Innovation Office. The title of Csaba Fábri's project is "Development of novel methods in quantum molecular dynamics", while the title of Tamás Szidarovszky's project is "Rovibrational control of polyatomic molecules using laser fields".
A research article authored by members of KKRK was featured on the front cover of the journal Physical Chemistry Chemical Physics. The paper presents a detailed analysis of the bound and metastable rovibrational states of the weakly-bound ArNO+ complex based on high-quality quantum mechanical simulations.
Professor Bill Poirier from Texas Tech University will stay in our group as a Hungarian Academy of Sciences Distinguished Guest Scientist until July this year. During his stay at KKRK, Professor Poirier will be involved in a joint project with KKRK, which focuses on the critical evaluation and validation of the complete set of previously published experimental rotational-vibrational line positions for the four stable sulphur isotopologues of the semirigid SO2 molecule. Professor Poirier will also give a lecture serier on quantum dynamics at the Eötvös Loránd University during the spring semester. Welcome to our group Bill!
A research article authored by members of KKRK was featured on the front cover of The Journal of Physical Chemistry A. The paper focuses on the large-scale spectroscopic networks generated by the rovibronic spectra of molecules. The efficient MARVEL (Measured Active Rotational–Vibrational Energy Levels) approach developed at KKRK as well as the merits of the graph theoretical approach to specroscopy are discussed in the article.
The International Association for the Properties of Water and Steam (IAPWS) plans to update its standard equation of state for the thermodynamic properties of heavy water, D2O. To help this effort, the KKRK team published highly-accurate thermodynamic data in the prestigeous Journal of Physical and Chemical Reference Data of NIST (National Institute of Standards and Technology of the USA), most importantly temperature-dependent ideal-gas partition functions in the 0-6000 K interval, for three heavy-water isotopologues, forming the basis of the Vienna Standard Mean Ocean Water (VSMOW). The results obtained, based on the joint use of nine million experimental and computed rovibrational energy levels determined by the KKRK team, have a number of terrestrial and extraterrestrial applications.
The 29th International Course and Conference on the Interfaces among Mathematics, Chemistry and Computer Sciences (Math/Chem/Comp, MC2-29) will be held between June 19–25, 2017, in Dubrovnik, Croatia under the joint auspices of the Inter-University Center, Dubrovnik, Croatia, the University of Zagreb, and the Rudjer Bošković Institute, Zagreb, Croatia. The first circular of the meeting has just become available.
The cover of the November 17, 2016 issue of the ACS journal J. Phys. Chem. A depicts an image associated with a review-like paper, entitled Small Molecules - Big Data, of three founding members of KKRK, Dr. Attila G. Császár, Dr. Tibor Furtenbacher, and Péter Árendás (working hard on finishing up his PhD thesis). According to the authors the marriage of high-resolution molecular spectroscopy and modern network theory offers several new and promising tools for improving our understanding of the complex nuclear dynamics of even small molecular systems. Furthermore, via the MARVEL approach built upon spectroscopic networks and developed extensively within KKRK, the network-theoretical approach serves well the needs of a wide range of modelers and engineers by helping the verification and systematization of line-by-line data deposited in spectroscopic databases (like HITRAN).
The September 7, 2016 issue of Phys. Chem. Chem. Phys. contains a research article co-authored by members of KKRK advertized on the inside back cover of the journal. The paper, prepared in collaboration with researchers from the University of Cambridge, UK, reports sophisticated quantum dynamical computations on the weakly bound, highly fluxional methane–water dimer and successfully interprets high-resolution far-infrared spectroscopic measurements which were left unexplained for more than two decades. At the same time, this collaborative research effort validates the intermolecular model potentials of this prototype of the water hydrocarbon interactions.
The research proposal of Mr. János Sarka, a member of KKRK, entitled "Investigation of rotational-vibrational energy levels of complex chemical systems based on variational nuclear motion computations" received support from the prestigeous ÚNKP program (New National Program of Excellence). The award will allow János to carry out research up until the end of June 2017 as a predoctoral fellow. Congratulations!
Prof. Thierry Stoecklin (Université de Bordeaux I) gave a successful lecture with the title "Vibrational sympathetic cooling of BaCl+ by Ca atoms: A theoretical study".
For the term 2016-2017, the Physical and Biophysical Chemistry Division (I) of IUPAC, the International Union of Pure and Applied Chemistry, appointed Attila G. Császár, the head of the research group, as a Titular Member (TM). After being an Associate Member between 2012-2015, Attila continues serving IUPAC's Division I in his new, more responsible role.
János Sarka, a second-year PhD student of ELTE and a member of the MTA-ELTE Complex Chemical Systems Research Group, has won the award of the American Chemical Society and the Journal of Physical Chemistry for his poster presentation "Higher-lying vibrational states of the H(5-n)Dn+ (n = 0-5) molecular ions" at the conference "Anharmonicity in medium-sized molecules and clusters", AMOC2015, held in Madrid, Spain between April 26-30, 2015. Co-authors of the poster were Dr. Csaba Fábri (ETH Zürich) and Prof. Attila G. Császár, the head of the research group. Congratulations to János for his outstanding achievement.
The COST action MOLIM (Molecules in Motion), proposed by Attila G. Csaszar, was approved for funding for the next four years. This is only the second approved COST action which was proposed by a Hungarian chemist and the first where the emphasis is tilted toward theoretical chemistry.
MOLIM, a multifaceted, multilinked, highly interdisciplinary COST Action will provide leadership for the development of computational tools for molecular sciences including determination of properties of complex non- and quasi-periodic systems, for the coupling of electronic and nuclear motions, and for the application of the new tools to experimental problems of an outstanding nature. MOLIM will also become the ground for the emergence of the next generation of chemists who will be users of the next generation of chemistry tools. The Action will start in March 2015 and will involve about 100 researchers from about 25 countries from the EU and the neighboring countries.
Essential Science Indicators of Thomson Reuters listed the "Highly Cited Papers" of 2014. This prestigeous list contains the paper C. Fábri, E. Mátyus, and A. G. Császár, Numerically Constructed Internal-Coordinate Hamiltonian with Eckart Embedding and Its Application for the Inversion Tunnelling of Ammonia, Spectrochim. Acta A 2014, 119, 84-89 (http://dx.doi.org/10.1016/j.saa.2013.03.090) , the first "highly cited paper" of the Research Group.
Tamás Szidarovszky, a fellow researcher of the ELTE-MTA Research Group on Complex Chemical Systems has received the prestigious JSPS (Japanese Society for the Promotion of Science) Postdoctoral Fellowship for his application titled "Dynamics of H2 in a molecular complex in intense laser fields". The research project is hosted by Professor Kaoru Yamanouchi from The University of Tokyo.
Recently Thomson Reuters started a new service identifying papers with an unusually high number of citations in the scientific literature (the top 1% of the papers published). In Essential Science Indicators they list "Highly Cited Papers", which are top cited papers over the past 10 years in each of 22 scientific fields. From Hungary, 673 papers appear on this list (containing 60806 entries), of which 33 papers are in chemistry. Five of these Highly Cited Papers are co-authored by Attila G. Csaszar, one from 2004 (J. Chem. Phys. 2004, 121, 11599), 2005 (J. Phys. Chem. Ref. Data 2005, 34, 573), 2006 (J. Chem. Phys. 2006, 125, 064108), 2012 (Phys. Rev. Lett. 2012, 108, 023002), and 2013 (J. Quant. Spectr. Rad. Transfer 2013, 117, 29). Tamas Szidarovszky is a co-author of the 2012, while Csaba Fabri and Tibor Furtenbacher are co-authors of the 2013 publication (http://dx.doi.org/10.1016/j.jqsrt.2012.10.002, http://dx.doi.org/10.1103/PhysRevLett.108.023002).
The article published in the open access journal of Nature Publishing Group (NPG) Scientific Reports provides several new ideas about the utilization of network theory in high-resolution molecular spectroscopy. The freely available article is based on the recent TDK work of Mr. Péter Árendás and contains beautiful visual representations of the first-principles spectroscopic networks of H216O in absorption and a minimum-weight spanning tree of the rotational transitions of the first three bands of para-H216O.
On the list of "most cited articles published since 2009" in the Journal of Quantitative Spectroscopy and Radiative Transfer two articles co-authored by Tibor Furtenbacher and Attila G. Császár appear at the 7th and 13th places. Both articles have been published on water spectroscopy by an IUPAC Task Group established in 2004. The two articles appeared in the journal in 2009 and 2010:
The IUPAC Technical Report "A database of water transitions from experiment and theory", co-authored by Attila Csaszar, is the second "most downloaded article" of 2014 in the IUPAC-owned journal Pure and Applied Chemistry. The article overviews the activities of an IUPAC Task Group established in 2004 and contains several recommendations about the spectroscopy of water vapor.
Tamás Szidarovszky, a fellow researcher of the ELTE-MTA Research Group on Complex Chemical Systems has received the Erdős Pál
Young Researcher Fellowship for his application titled "Molecules beyond dissociation: non-hermitian quantum chemistry".
Congratulations!
The Center for Computational Quantum Chemistry (CCQC) of the University of Georgia has a couple of prestigious Named Lectures Series, including the Robert S. Mulliken Lectures. Attila Császár was invited to Athens, GA to present the 2014 Robert S. Mulliken Lecture on March 7, 2014. A plaque presented to Attila at the beginning of his lecture explained the invitation by his many pioneering contributions to theoretical chemistry. The title of the presentation was The fourth age of quantum chemistry Molecules in motion. The Mulliken Lecture overviewed the many recent developments achieved in the MTA-ELTE Research Group on Complex Chemical Systems and the Laboratory of Molecular Structure and Dynamics within the fields of nuclear motion theory and quantum chemistry. The impressive list of previous Robert S. Mulliken lecturers includes Nobel laureates Dudley R. Herschbach (2001), Yuan T. Lee (2002), and Rudolph A. Marcus (2006).
The first publication of the Research Group appeared in the prestigious journal of the Royal Society, Chemical Science (2013, 4, 4362), http://dx.doi.org/10.1039/C3SC52157E. The article entitled "Dynamics of the F- + CH3CL -> Cl- + CH3F SN2 reacion on a chemically accurate potential energy surface" is featured on the back cover of the Journal.
Prof. Attila Császár received a prestigious 5-year grant from the Hungarian Academy of Sciences (MTA) to establish a new research group, called MTA-ELTE Research Group on Complex Chemical Systems, at Eötvös University (ELTE).