A5029056296- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Education, Psychology, and Social Research
- Magnetism in coordination complexes
- Catalysis and Oxidation Reactions
- Advanced NMR Techniques and Applications
- Molecular Junctions and Nanostructures
- Graphene research and applications
- Machine Learning in Materials Science
- Matrix Theory and Algorithms
- Quantum and electron transport phenomena
- Perovskite Materials and Applications
- Photochemistry and Electron Transfer Studies
- Physics of Superconductivity and Magnetism
- Quantum many-body systems
- Surface Chemistry and Catalysis
- Molecular spectroscopy and chirality
- Synthesis and Properties of Aromatic Compounds
- Fullerene Chemistry and Applications
- Electrocatalysts for Energy Conversion
- Distributed and Parallel Computing Systems
- Adhesion, Friction, and Surface Interactions
- Topological Materials and Phenomena
- Metalloenzymes and iron-sulfur proteins
- CO2 Reduction Techniques and Catalysts
Czech Academy of Sciences, J. Heyrovský Institute of Physical Chemistry
2014-2024
Institute for Advanced Study
2023
Charles University
2023
HUN-REN Wigner Research Centre for Physics
2023
Technical University of Munich
2023
John Wiley & Sons (United States)
2012-2021
Lawrence Berkeley National Laboratory
2015-2017
Environmental Molecular Sciences Laboratory
2012
Pacific Northwest National Laboratory
2012
Battelle
2012
Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support guide experimental efforts for prediction atomistic electronic properties. In this regard, structure played a special role using first-principle-driven methodologies model complex processes. Over past few decades, rapid development computing technologies tremendous increase in power offered unique chance study transformations sophisticated...
In the past decade, quantum chemical version of density matrix renormalization group (DMRG) method has established itself as choice for calculations strongly correlated molecular systems. Despite its favorable scaling, it is in practice not suitable computations dynamic correlation. We present a novel accurate "post-DMRG" treatment correlation based on tailored coupled cluster (CC) theory which DMRG responsible proper description nondynamic correlation, whereas incorporated through framework...
The ability to engineer geometrically well-defined antidots in large triangulene homologues allows for creating an entire family of quantum rings (TQRs) with tunable high-spin ground state, crucial next-generation molecular spintronic devices. Herein, we report the synthesis open-shell [7]triangulene ring ([7]TQR) molecule on Au(111) through surface-assisted cyclodehydrogenation a rationally designed kekulene derivative. Bond-resolved scanning tunneling microscopy (BR-STM) unambiguously...
The new generation of proposed light-emitting molecules for organic diodes (OLEDs) has raised considerable research interest due to its exceptional feature─a negative singlet–triplet (ST) gap violating Hund's multiplicity rule in the excited S1 and T1 states. We investigate role spin polarization mechanism ST inversion. Spin is associated with doubly determinants certain types, whose presence wave function expansion favors energy singlet state more than that triplet. Using a perturbation...
The character of the electronic structure acenes has been subject longstanding discussion. However, convincing experimental evidence their open-shell so far missing. Here, we present on-surface synthesis tridecacene molecules by thermal annealing octahydrotridecacene on a Au(111) surface. We characterized scanning probe microscopy, which reveals presence an inelastic signal at 126 meV. attribute to spin excitation from singlet diradical ground state triplet excited state. To rationalize...
The seventh part of the series on distributions vascular plants in Czech Republic includes grid maps 104 taxa genera Anthriscus, Callitriche, Cochlearia, Dittrichia, Egeria, Elodea, Elymus, Epilobium, Gentianella, Gnaphalium, Gymnocarpium, Hordeum, Hydrocharis, Limonium, Najas, Phleum, Phragmites, Polypodium, Pseudognaphalium, Rubus, Sedum, Senecio, Setaria, Stratiotes, Trichomanes and Woodsia. These were produced by taxonomic experts based examined herbarium specimens, literature field...
Abstract We present, to the best of our knowledge, first attempt exploit super‐computer platform for quantum chemical density matrix renormalization group (QC‐DMRG) calculations. have developed parallel scheme based on in‐house MPI global memory library, which combines operator and symmetry sector parallelisms, tested its performance three different molecules, all typical candidates QC‐DMRG In case largest calculation, is nitrogenase FeMo cofactor cluster with active space comprising 113...
The synthesis of polycyclic aromatic hydrocarbons containing various non-benzenoid rings remains a big challenge facing contemporary organic chemistry despite considerable effort made over the last decades. Herein, we present novel route, employing on-surface chemistry, to synthesize nonalternant up four distinct kinds rings. We show that surface-induced mechanical constraints imposed on strained helical reactants play decisive role leading formation products, energetically unfavorable in...
In this article, we investigate the numerical and theoretical aspects of coupled-cluster method tailored by matrix-product states. We formal properties used method, such as energy size consistency equivalence linked unlinked formulation. The existing mathematical analysis is here elaborated in a quantum chemical framework. particular, highlight use what have defined complete active space-external space gap describing basis splitting between external part generalizing concept HOMO-LUMO gap....
Polycyclic aromatic hydrocarbons (PAHs) are a family of organic compounds comprising two or more fused rings which feature manifold applications in modern technology. Among these species, those presenting an open-shell magnetic ground state particular interest for electronic, spintronic, and non-linear optics energy storage devices. Within PAHs, special attention has been devoted recent years to the synthesis study acene (periacene) families, steered by their decreasing HOMO–LUMO gap with...
The synthesis of novel polymeric materials with porphyrinoid compounds as key components the repeating units attracts widespread interest from several scientific fields in view their extraordinary variety functional properties potential applications a wide range highly significant technologies. vast majority such polymers present closed-shell ground state, and, only recently, result improved synthetic strategies, engineering open-shell spin delocalization along conjugation length has been...
The concept of the model space underlying multireference coupled-cluster (MRCC) formulations is a powerful tool to deal with complex correlation effects for various electronic states. Here, we demonstrate that iterative state-specific MRCC methods (SS-MRCC) based on properly defined spaces can be used describe core-level excited states even when Hartree-Fock orbitals are utilized. We show SS-MRCC models single and double excitations comparable in accuracy high-level reference...
We present a special symmetric Lanczos algorithm and kernel polynomial method (KPM) for approximating the absorption spectrum of molecules within linear response time-dependent density functional theory (TDDFT) framework in product form. In contrast to existing algorithms, new algorithms are based on reformulating original non-Hermitian eigenvalue problem as observation that is self-adjoint with respect an appropriately chosen inner product. This allows simple be used compute desired...
This article reports development of a local variant Mukherjee's state-specific multireference coupled cluster method based on the domain-based pair natural orbital approach (DLPNO-MkCC). The current implementation is restricted to connected single and double excitations model space with up biexcited references. performance DLPNO-MkCCSD was tested calculations tetramethyleneethane. results show that above 99.9% correlation energy recovered, respect conventional MkCC method. To demonstrate...
Active space quantum chemical methods could provide very accurate description of strongly correlated electronic systems, which is tremendous value for natural sciences. The proper choice the active crucial but a nontrivial task. In this article, we present neural network-based approach automatic selection spaces, focused on transition metal systems. training set has been formed from artificial systems composed one and various ligands, have performed density matrix renormalization group...
Iron-sulfur clusters comprise an important functional motif in the catalytic centers of biological systems, capable enabling chemical transformations at ambient conditions. This remarkable capability derives from a notoriously complex electronic structure that is characterized by high density states sensitive to geometric changes. The spectral sensitivity subtle changes has received little attention correlated, large active space calculations, owing partly exceptional computational...
Tensor algebra operations such as contractions in computational chemistry consume a significant fraction of the computing time on large-scale platforms. The widespread use tensor between large multi-dimensional tensors describing electronic structure theory has motivated development multiple frameworks targeting heterogeneous In this paper, we present Algebra for Many-body Methods (TAMM), framework productive and performance-portable scalable methods. TAMM decouples specification computation...
We performed an ab initio study of the singlet-triplet gap in trimethylenmethane (TMM) and ring-opening methylenecyclopropane by multireference BWCC method. Since singlet states TMM intermediates between have a strong multiconfigurational character, it is necessary to use The cc-pVDZ cc-pVTZ basis sets were used. compared our results with experiments, where available, previous calculations MCSCF spin-flip coupled-cluster-type methods.
Iron–sulfur clusters are crucial for biological electron transport and catalysis. Obtaining accurate geometries, energetics, manifolds of their excited electronic states, reduction energies is important to understand role in these processes. Using a [2Fe–2S] model complex with FeII FeIII oxidation which leads different charges, i.e., [Fe2S2(SMe)4]2–,3–,4–, we benchmarked variety computational methodologies ranging from density functional theory (DFT) post-Hartree–Fock methods, including...
A novel algorithm for implementing a general type of multireference coupled-cluster (MRCC) theory based on the Jeziorski-Monkhorst exponential ansatz [Jeziorski, B.; Monkhorst, H. J. Phys. Rev. A1981, 24, 1668] is introduced. The proposed utilizes processor groups to calculate equations MRCC amplitudes. In basic formulation, each group constructs related specific subset references. By flexible choice and reference-specific sufficiency conditions designated given group, one can ensure optimum...
We present a new implementation of density matrix renormalization group based tailored coupled clusters method (TCCSD), which employs the domain-based local pair natural orbital approach (DLPNO). Compared to previous (LPNO) version method, is more accurate, offers favorable scaling, and provides consistent behavior across variety systems. On top singles doubles, we include perturbative triples correction (T), able retrieve even dynamic correlation. The methods were tested on three systems:...