A5014296154- Advanced Chemical Physics Studies
- Photochemistry and Electron Transfer Studies
- Spectroscopy and Quantum Chemical Studies
- Atomic and Molecular Physics
- Inorganic Fluorides and Related Compounds
- Atmospheric Ozone and Climate
- Porphyrin and Phthalocyanine Chemistry
- Synthesis and Characterization of Pyrroles
- Atmospheric chemistry and aerosols
- Electron and X-Ray Spectroscopy Techniques
- Molecular Spectroscopy and Structure
- Synthetic Organic Chemistry Methods
- Molecular Junctions and Nanostructures
- Fluorine in Organic Chemistry
- X-ray Spectroscopy and Fluorescence Analysis
- Catalytic Alkyne Reactions
- Luminescence Properties of Advanced Materials
- Cyclopropane Reaction Mechanisms
- DNA and Nucleic Acid Chemistry
- Asymmetric Synthesis and Catalysis
- Spectroscopy and Laser Applications
- Organic Chemistry Cycloaddition Reactions
- Crystallography and molecular interactions
- Luminescence and Fluorescent Materials
- Various Chemistry Research Topics
Irkutsk State University
2016-2025
Siberian Branch of the Russian Academy of Sciences
2008-2025
A.E. Favorsky Irkutsk Institute of Chemistry
2015-2024
Heidelberg University
1993-2009
University of Chicago
2008-2009
KTH Royal Institute of Technology
2009
Elettra-Sincrotrone Trieste S.C.p.A.
2009
University of Illinois Chicago
2005-2008
Kansas State University
2004
A practical polarization propagator method devised for the treatment of valence electron excitations in atoms and molecules is presented. This method, referred to as (second-order) algebraic-diagrammatic construction (ADC(2)), allows a theoretical description single double consistently through second first order, respectively, perturbation theory. The computational scheme essentially an eigenvalue problem Hermitian secular matrix defined with respect space singly doubly excited...
Propagator methods provide a direct approach to energies and transition moments for (generalized) electronic excitations from the ground state, but they do not usually allow one determine excited state wave functions properties. Using specific intermediate representation (ISR) concept, we here show how this restriction can be overcome in case of algebraic-diagrammatic construction (ADC) propagator approach. In ISR reformulation theory basic ADC secular matrix is written as Hamiltonian (or...
The K-shell excitation spectra of the hydrides water, ammonia, and methane have been measured in photoabsorption experiments using synchrotron radiation combination with a high-resolution monochromator. For case methane, particular, wealth spectral detail is observed which was not accessible previous studies. energies relative intensities compare well values calculated complete second-order approximation for polarization propagator. In order to determine extent admixing valence excitations...
An efficient third-order propagator method to compute ionization potentials and electron affinities of atoms molecules is presented. The development based on the algebraic diagrammatic construction (ADC) representing a specific reformulation perturbation series G(ω). In contrast with previous approximation schemes, relying Dyson equation approximations for self-energy part, ADC procedure here applied directly (N∓1)-electron parts G−(ω) G+(ω), respectively, propagator. This leads decoupled...
A propagator method referred to as third-order algebraic–diagrammatic construction [ADC(3)] for the direct computation of electronic excitation energies and transition moments is presented. This approach based on a specific reformulation diagrammatic perturbation expansion polarization propagator, extends existing second-order [ADC(2)] scheme next level theory. The computational combines diagonalization Hermitian secular matrix theory elements. characteristic properties are compact...
The complete valence shell photoelectron spectra of cytosine, thymine and adenine have been investigated experimentally theoretically. Vertical ionization energies spectral intensities evaluated using the many-body Green's function method, thereby enabling theoretical to be derived. In influence tautomers rotational conformers has investigated. calculated display a satisfactory agreement with experimental data this allowed most bands assigned. Photoelectron asymmetry parameters determined...
The O, N, and C 1s core level photoemission spectra of the nucleobases cytosine uracil have been measured in vapor phase, results interpreted via theoretical calculations. Our calculations accurately predict relative binding energies features observed experimental provide a full assignment. In agreement with previous work, single tautomer is populated at 405 K, giving rise to relatively simple spectra. At 450 three tautomers cytosine, one which may consist two rotamers, are identified, their...
An earlier proposed propagator method for the treatment of molecular ionization is tested in first applications. The referred to as non-Dyson third-order algebraic-diagrammatic construction [nD-ADC(3)] approximation electron represents a computationally promising alternative existing Dyson ADC(3) method. advantage nD-ADC(3) scheme that (N+/-1)-electronic parts one-particle Green's function are decoupled from each other and corresponding equations can be solved separately. For test results...
An earlier proposed approach to molecular response functions based on the intermediate state representation (ISR) of polarization propagator and algebraic-diagrammatic construction (ADC) approximations is for first time employed calculations nonlinear properties. The two-photon absorption (TPA) spectra are considered. hierarchy first- second-order ADC/ISR computational schemes, ADC(1), ADC(2), ADC(2)-x, ADC(3/2), tested in applications H2O, HF, C2H4 (ethylene). calculated TPA compared with...
A recently developed consistent third-order propagator method for the treatment of electronic excitation in molecules is tested first applications. The referred to as algebraic-diagrammatic construction [ADC(3)] extends existing second-order approximation and aims at a more accurate computation energies transition moments than afforded level. For stringent test we compare ADC(3) over 40 singlet triplet vertical transitions H2O, HF, N2, Ne with results recent full configuration interaction...
The valence ionization bands of benzene and polyacenes ranging from naphthalene to pentacene have been entirely assigned by means one-particle Green’s function calculations, performed using the third-order algebraic-diagrammatic construction [ADC(3)] scheme series basis sets improving quality. For sake consistency, computations are based on correlated (DFT/B3LYP) rather than uncorrelated geometries. Ionization pertaining π-orbitals subject a severe shake-up contamination at already quite low...
Intermolecular Coulombic decay (ICD) is considered a general phenomenon that plays key role in many fundamental and applied fields related to biological environments. In cases, however, the mechanisms efficiency of ICD have yet be uncovered. A prominent example heavy-ion cancer therapy. Here, we report first detection damaging intermolecular relaxation cascade initiated by bombardment hydrated pyrimidine clusters. The process can significantly contribute high effectiveness irradiation thus...
It was demonstrated that alkynyl halides could serve as a source of Br+ and acetylide ions in the same transformation. This allowed for efficient one-step preparation epoxides, important organic building blocks, from readily available starting materials.
The first highly efficient, diastereo- and regioselective transition metal-catalyzed addition of metal hydrides (stannanes, silanes, germanes) bimetallic species (ditins silyltins) to cyclopropenes has been developed. It was shown that the across double bond is generally controlled by steric factors proceeds from least hindered face. This methodology represents a powerful atom-economic approach toward wide variety substituted stereodefined cyclopropylmetals, useful building blocks...
The core level photoemission and near edge X-ray photoabsorption spectra of guanine in the gas phase have been measured results interpreted with aid high ab initio calculations. Tautomers are clearly identified spectroscopically, their relative free energies Boltzmann populations at temperature experiment (600 K) calculated compared experimental previous We obtain good agreement between weighted theoretical spectra, which allows a quantitative determination ratio oxo to hydroxy tautomer...
The A22 and B12 states formed in the ionization of outermost π orbitals furan, pyrrole thiophene are shown to interact vibronically via nontotally symmetric b2 vibrational modes. interaction is strongest thiophene, where conical intersection between two adiabatic surfaces occurs near minimum upper (B12) state. resulting nonadiabatic effects manifest themselves bands by a lack resolved structure case line broadening furan. spectra investigated using linear vibronic coupling model. All totally...
The valence shell photoelectron spectrum of purine has been studied experimentally and theoretically. Synchrotron radiation used to record spectra at photon energies 45 85 eV. Photoelectron angular distributions have determined these provide an experimental means distinguishing between σ-and π-type orbitals. Vertical ionization spectral intensities evaluated using the many-body Green function method. calculated agree well with results in outer region proved be indispensable for interpreting...
Polarization of the triple bond in a series differently substituted ortho- and para-tolanes has been studied by NMR computational methods order to examine if 13C data can be effectively used for assessment electronic polarization diarylacetylenes. DFT calculations both natural charges properties revealed that chemical shifts concur with effective on sp-carbon atoms para-tolanes, whereas ortho-analogues magnetic anisotropy complicates analysis making inapplicable ascribing polarization. The...
The third-order non-Dyson algebraic-diagrammatic construction approach to the electron propagator [IP-ADC(3)] is extended using intermediate state representation (ISR) formalism, allowing wave functions and properties of molecular states with detached be studied. second-order ISR equations [ISR(2)] for one-particle (transition) density matrix have been derived implemented in Q-CHEM program. completely general enables evaluation arbitrary operators interpretation detachment processes terms...
The lowest two Rydberg and π–π* valence excited singlet states of furan [referred to as A11(3s), B11(3p) B12(V), A11(V′), respectively, at the C2v ground-state molecular configuration] have been studied using equation-of-motion coupled-cluster singles doubles method (EOM-CCSD). Full geometry optimizations with subsequent computation harmonic vibrational frequencies performed in order locate characterize stationary points on potential energy surfaces (PES). latter optimization work was...