2022 Assoc. Prof. V. Klimavičius have received additional support from VU foundation
Assoc. Prof. Vytautas Klimavičius, a young researcher from the Institute of Chemical Physics, have won an additional scholarship provided by the VU Foundation. It is intended for successful integration at Vilnius University for talented young scientists who have substantial international experience. Vytautas has spent three years at the Technical University of Darmstadt in Germany. He also had internships in Poland, Slovenia, and won the prestigious Alexander von Humboldt Foundation fellowship for postdoctoral researchers.
The director of VU foundation J. Noreika with the laureate V. Klimavičius
Assoc. Vytautas Klimavičius knowledge on the solid-state nuclear magnetic resonance (NMR) spectroscopy and its applications for studying functional materials will be applied at the Institute of Chemical Physics of the Faculty of Physics. The young scientist's field of research also includes Dynamic Nuclear Polarization (DNP), currently one of the most promising areas of NMR hyperpolarization.
Dr. Vytautas Klimavičius maintains fruitful collaborations with colleagues from Germany, France, Poland, Japan, USA, etc. The researcher's international relations will strengthen the scientific group of Magnetic Resonance at the Institute of Chemical Physics, as well as the international competitiveness of VU.
From right: Dean of the Faculty of Physics J. Šulskus, group leader of Magnetic Resonance V. Balevičius,
laureate V. Klimavičius and the director of the Institute of Chemical Physics V. Šablinskas are glad for the support provided by VU Foundation (2022 09 22)
LMT grant for Researcher groups project “Modelling of structural and spectroscopic NMR properties of bio-active ionic-liquid materials” (2022-04-01 – 2025-03-31) is received
Project team: dr. Kęstutis Aidas (project leader), dr. Dovilė Lengvinaitė, PhD st. Žyginta Einorytė, dr. Vytautas Klimavičius.
Budget: € 149908.
Abstract
Ionic liquids are substances composed of solely organic cations and organic or inorganic anions, and they have already found important applications in both industry and academia thanks to their unique properties such as negligible vapor pressure, high ionic conductivity, thermal stability and high solvating power of a wide variety of materials. In particular, the so-called 3rd generation ionic liquids are composed of bio-active materials such as choline and amino acids, and thereby they present lower toxicities leading to potential applications as pharmaceuticals. Indeed, the conversion of drugs or bio-active molecules into ionic liquids represents the strategy to improve some issues related to solubility, polymorphism and bioavailability. By choosing appropriate counterions, it is possible to obtain biocompatible and environmentally friendly ionic liquids. To rationalize the mechanisms behind the physico-chemical properties and bio-activity of IL materials, detailed understanding of intermolecular structure and dynamics of these heterogeneous systems is required. Nuclear magnetic resonance (NMR) spectroscopy has proven to be a useful tool in structural and dynamical investigations of IL systems. However, interpretation of experimental NMR data is often complicated due to the complex chemical equilibrium between various kinds of ionic aggregates and due to the inherent heterogeneities in the ILs. This project is aimed at developing a computational procedure that would allow for accurate prediction of NMR shielding constants of IL systems and thus would provide the means for a well-motivated interpretation of experimental NMR spectra. Our approach is based on the classical molecular dynamics simulations and on the combined quantum mechanics/molecular mechanics models. One of the advantages of proposed computational scheme is due to the fact that different types of intermolecular interactions which govern the physico-chemical properties of ILs can be modelled in an accurate and cost-effective manner. The computational procedure developed in this project will be applied to get important insight into – among other things – ion pairing phenomenon in IL solutions, formation of the so-called water pockets in the IL matrices, and the mechanism behind the increased solubility of drugs in the mixtures of bio-active ILs and water.
LMT grant for Researcher groups project “Development of cross-linkable structures for solar cells” (2022-04-01 – 2025-03-31) is received
Project team: dr. Vygintas Jankauskas (project leader), dr. Kristijonas Genevičius, dr. Egidijus Kamarauskas, dr. Valentas Gaidelis, PhD. St. Povilas Luižys (KTU), PhD st. Romualdas Jonas Čepas, dr. Jonas Nekrasovas.
Project budget: € 149993.
Abstract
Development of cheap photodetectors, solar cells, photodiodes or other optoelectronic devices is associated with organic and hybrid structures. As an example of such devices bulk heterojunctions and perovskite solar cells, lead oxide X-ray detectors, and light emitting diodes could be mentioned. The main advantages of organic materials are solution processability and possibility to tune the properties of molecules by changing functional groups, the main disadvantages are photochemical degradation and low charge carrier mobility. Mobility of charge carriers determines operational speed (or efficiency) of the devices, degradation of materials reduces the lifetime of the devices and also affects mobility of charge carriers. Therefore, special attention should be paid to these properties of materials. When fabricating multilayer organic structures from the solution, there is a risk of dissolution of the lower layers. The best way to overcome this problem is to form additional chemical bonds between the molecules and to form cross-linked layers. After cross-linking, organic layer becomes more resistant (mechanically and chemically) and insoluble, but this can change the packing of the molecules and at the same time properties of charge carriers transport.
The main objective of this project is the photo-electrical characterization of new and already existing cross-linkable hole and electron transporting materials and test their possible application in solar cells. During the project, existing and new hole transporting fluorene, carbazole or triphenylamine derivatives and electron transport naphthalene or perylene derivatives with reactive styrene groups will be investigated. The main focus of the research will be paid to determination of optimal cross-linking conditions, investigation of charge carriers transport and estimation of HOMO and LUMO energies before and after cross-linking. The most promising materials will be used in the fabrication and characterization of multilayer solar cells (bulk heterojunction, perovskite or CZTS) with the focus on efficiency and stability.
The Lithuanian National HPC Competence Center is being established at Vilnius University (2020-2022)
The Lithuanian National HPC Competence Center is being established at Vilnius University (2020-2022)
Vilnius University (VU) is involved into Europe international HPC (or supercomputing) Competence Center projects EuroCC and CASTIELVU researchers dr. Povilas Treigys (Faculty of Mathematics and Informatics) and dr. Mindaugas Mačernis (Faculty of Physics) are participating in these projects by running Lithuanian national HPC competence center. EuroCC works closely with the CASTIEL project, which together will ensure the consistent dissemination of high-end supercomputing experiences across Europe.
EuroCC is an extremely wide supercomputing competence network across Europe
A total of 32 countries with available supercomputing resources and their national competence centers are participating in EuroCC project. Projects aim to facilitate the use of best practice HPC practices in high-performance computing centers in order to use excascale type supercomputers in near future. Supercomputers consist of thousands of processors that analyze billions of data in real time and supercomputer performs various calculations thousands of times faster than a normal computer. However, it is not triaval task to use them and high level HPC compentences are needed.
The EuroCC and CASTIEL projects will help address existing HPC skills issues and promote collaboration and sharing of experiences between different countries, both within the country and across Europe. The project will create a pan-European HPC competency map that reflects the resources available and the level of knowledge in all EuroCC national competence centers. This will encourage cooperation, exchange of good practices, sharing of knowledge between different organizations and countries. In Lithuanian case, the HPC competence could acquire Lithuanian citizens, institutions and companies in order to use supercomputing infrastructures which are located inside and outside Lithuania.
“Through these EuroCC and CASTIEL projects, the HPC Competence Centers will bridge the gap between competencies and provide opportunities for academia, medium and small businesses to acquire broader supercomputer competencies. In many cases, only very large industries have enough knowledge on how to be superior in the market by using supercomputers,” says Dr. M. Mačernis.
Digital competences are an integral part of everyday life
Each of the 32 national centers of excellence that will be part of the EuroCC network operate as national HPC digital centers of excellence in individual countries. This will allow researchers, public administrations, as well as various industries to take advantage of the opportunities offered by supercomputers. On the other hand, CATIEL as umbrella EuroCC project coordinates activities between national centers.
"Digital competencies - one of the most important things not only for the development and implementation of new technologies - they help to orientate in the modern world and perform many important tasks from the purchase of goods and payment of bills to professional work," says Dr. P. Treigys.
According to the researcher, digital literacy and competences still overtake a significant part of society, which is why digital skills are not used as widely in everyday life as is often required by the changing living environment and especially new technologies. The project will aim to make supercomputers available to as many stakeholders as possible.
“The projects will collaborate with all interested, potential and existing supercomputer users. In addition, there are opportunities in other activities - possible joint European master's studies or access to one of the most powerful supercomputers in the world, ”says dr. M. Mačernis.
The possibilities provided by supercomputers arealso taken at VU
VU two faculties Physics, Mathematics and Informatics in the field of productive computing will soon be able to offer the scientific community petaflop computing power resources for solving problems.
"In order to optimally use the possibilities provided by supercomputers, it is not enough to have only technical resources. It is necessary to cultivate and improve one’s competencies, for example by sharing good practices. This is exactly the opportunity to participate in the EuroCC and CASTIEL projects. In addition, Lithuania became a member of EuroHPC, which opened the possibility for VU to become the Lithuanian national HPC competence center and to be a partner in these projects, ”says Dr. P. Treigys
The EuroCC and CASTIEL projects are running from 2020 September 1 until 2022 31 August, the total budgets of the projects are 59 million EUR. EuroCC project has received funding from the European High-Performance Computing Joint Undertaking Joint Undertaking (JU) under grant agreement No 951732. The JU receives support from the European Union’s Horizon 2020 research and innovation programme and Germany, Bulgaria, Austria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Greece, Hungary, Ireland, Italy, Lithuania, Latvia, Poland, Portugal, Romania, Slovenia, Spain, Sweden, United Kingdom, France, Netherlands, Belgium, Luxembourg, Slovakia, Norway, Switzerland, Turkey, Republic of North Macedonia, Iceland, Montenegro.
Funding for SMART project Magneto-plasmonic nanoparticles for SERS at biological surfaces is recently received
World-class R&D Project (SMART) "Magneto‐plasmonic nanoparticles for SERS at biological surfaces (SM‐ARTSERS)"
The duration of the project: 2020.07 – 2023.10
Prof. Valdas Šablinskas (VU) and prof. Gediminas Niaura (FTMC)
This project is result of tight collaboration between Molecular Spectroscopy group of Institute of Chemical Physics at Vilnius University (VU) (the head – prof. Valdas Šablinskas) and Spectroelectrochemistry laboratory at Center for Physical Sciences and Technology (FTMC) (the head – prof. Gediminas Niaura). VU is participating in the project as FTMC partner. The project is considered to belong to the priority field “Advanced Materials and Constructions” in Smart Specialization program conducted in Lithuania.
The main goal of the project – to develop very sensitive and reproducible SERS substrates consisting from magneto-plasmonic nanoparticles made by laser ablation method. Creation of the hybrid nanostructure by the laser ablation method does not demand the use of organic compounds (as a reducing or stabilising agent) what eliminates the contamination of the nanoparticles. The hybrid nanostructures will consist from two parts: magnetic (Fe/FexOy) and plasmonic (Au/Ag). The magnetic part will allow easy manipulation of the nanoparticles by operating external magnetic field (separation from the solution, concentration of the analyte, positioning at the top of the substrate). The plasmonic part will be employed for enhancement of the SERS signal.
It is expected that the results obtained during this project will accelerate the translation of the SERS method from the labs to the biotechnological companies and clinical trials.
A new publication in The Journal of Chemical Physics
A new publication has been published by prof. D. Abramavičius group in The Journal of Chemical Physics. In the paper a relaxation problem of a system coupled to a bath of harmonic oscillators is described. While the problem seems to be a standard one, the problem becomes interesting when the environment relaxation time is not defined and diverges. Such type of problematics may be highly relevant for biological samples. This relaxation problem is not "solved" in the paper, while the problematics of relaxation is discussed in great detail and some approximate approaches are proposed.
Long memory effects in excitonic systems dynamics: Spectral relations and excitation transport J. Chem. Phys. 152, 244114 (2020); https://doi.org/10.1063/5.0009926 S. Korsakas, J. Bučinskas, and D. Abramavicius
Abstract: The main quantity that controls excitation relaxation and transport in molecular systems is the environment-induced fluctuation correlation function. Commonly used models assume the exponentially decaying correlation function, characterized by a given characteristic time, which allows us to define the Markovian conditions and, hence, allows us to use rate equations for excitation dynamics. A long memory fractional correlation function is studied in this paper as an alternative model. Such a function has an infinite characteristic decay time, and thus, system decay to equilibrium becomes poorly defined. Consequently, it becomes impossible to define the Markovian regime. By assuming the weak system–bath coupling regime, we apply the non-Markovian equations of motion to describe the equilibration process in an excitonic molecular aggregate. The long memory model causes a weaker decay of coherent components in excitonic system relaxation dynamics. Nevertheless, the short time dynamics, which is important in optical spectroscopy, depends on the short time interval of the fluctuation correlation function. Excitation relaxation in this window appears to be well described by non-Markovian approaches.