Wavefunction-based method for excited-state electron correlations in periodic systems - application to polymers

A systematic method for determining correlated wavefunctions of extended systems in the ground and excited states is presented. It allows to fully exploit the power of quantum-chemical programs designed for correlation calculations of finite molecules. Using localized Hartree-Fock (HF) orbitals (both occupied and virtual ones), an effective Hamiltonian which can easily be transferred from finite to infinite systems is built up. Correlation corrections to the matrix elements of the effective Hamiltonian are derived from clusters. To treat correlation effects, multireference configuration interaction (MRCI) calculations with singly and doubly excited configurations (SD) are performed. This way one is able to generate both valence and conduction bands where all correlation effects in the excited states as well as in the ground state of the system are taken into account. An appropriate size-extensivity correction to the MRCI(SD) correlation energies is developed which takes into account the open-shell character of the excited states. This approach is applicable to a wide range of polymers and crystals. In the present work trans-polyacetylene is chosen as a test system. The corresponding band structure is obtained with the correlation of all electrons in the system being included on a high level of sophistication. The account of correlation effects leads to substantial shifts of the "center-of-mass" positions of the bands (valence bands are shifted upwards and conduction bands downwards) and a flattening of all bands compared to the corresponding HF band structure. Further an extention of the above approach to excitons (optical excitations) in crystals is developed which allows to use standard quantum-chemical methods to describe the electron-hole pairs and to finally obtain excitonic bands.Comment: 111 pages, 23 figures, Ph.D. Thesi

Comparative and legal study of the concept of crime under legislation of CIS countries

This article analyzes the concept of crime under the criminal law of CIS countries, and reveals the specifics of the signs that make up this concept. The present study is based on the features that are most often found in the legislation of CIS countries. Approaches to the description and determination of the sign of public danger are studied and analyzed, and on this basis, the concept of criminal misconduct and insignificant action has been studied. It is revealed that the criminal legislation of selected states is described by its heterogeneity, and there are absolutely specific characteristics that are specified for individual countries

Genericity in Topological Dynamics

We study genericity of dynamical properties in the space of homeomorphisms of the Cantor set and in the space of subshifts of a suitably large shift space. These rather different settings are related by a Glasner-King type correspondence: genericity in one is equivalent to genericity in the other. By applying symbolic techniques in the shift-space model we derive new results about genericity of dynamical properties for transitive and totally transitive homeomorphisms of the Cantor set. We show that the isomorphism class of the universal odometer is generic in the space of transitive systems. On the other hand, the space of totally transitive systems displays much more varied dynamics. In particular, we show that in this space the isomorphism class of every Cantor system without periodic points is dense, and the following properties are generic: minimality, zero entropy, disjointness from a fixed totally transitive system, weak mixing, strong mixing, and minimal self joinings. The last two stand in striking contrast to the situation in the measure-preserving category. We also prove a correspondence between genericity of dynamical properties in the measure-preserving category and genericity of systems supporting an invariant measure with the same property.Comment: 48 pages, to appear in Ergodic Theory Dynamical Systems. v2: revised exposition, added proof that the universal odometer is generic among transitive Cantor homeomorphism

Ring closing metathesis strategies to isoxazole containing thiadiazepines

Cyclic sulfamides are attractive molecules with potential application in medical chemistry. It is known that thiadiazepine-containing derivatives demonstrate promising value in the development of protease inhibitors such as HIV protease, serine protease and metaloprotease. We demonstrate here a comfortable synthetic sequence to symmetric thiadiazepines containing isoxazole substitutents. The structure of the obtained substances was confirmed by 1H, 13C NMR spectroscopy

Diameter-Selective Dispersion of Carbon Nanotubes via Polymers: A Competition between Adsorption and Bundling

The mechanism of the selective dispersion of single-walled carbon nanotubes (CNTs) by polyfluorene polymers is studied in this paper. Using extensive molecular dynamics simulations, it is demonstrated that diameter selectivity is the result of a competition between bundling of CNTs and adsorption of polymers on CNT surfaces. The preference for certain diameters corresponds to local minima of the binding energy difference between these two processes. Such minima in the diameter dependence occur due to abrupt changes in the CNT's coverage with polymers and their calculated positions are in quantitative agreement with preferred diameters, reported experimentally. The presented approach defines a theoretical framework for the further understanding and improvement of dispersion/extraction processes.Comment: 22 pages, 5 figures, ACS Nano (2015

Current states in superconducting films: numerical results

We present numerical solutions of Aslamazov–Lempitskiy (AL) equations for distributions of the transport current density in thin superconducting films in the absence of external magnetic field, in both the Meissner and the vortex states. These solutions describe smooth transition between the regimes of a wide film and a narrow channel and enable us to find critical currents and current-voltage characteristics within a wide range of the film width and temperature. The normalized critical currents and the electric field were found to be universal functions of the relation between the film width and the magnetic field penetration depth. We calculate the fitting constants of the AL theory and propose approximating formulas for the current density distributions and critical currents

Histomorphology of trauma in charred and decomposed remains

Decomposition and burning of human remains are frequently encountered in forensic cases, and pose a challenge at determining an accurate cause of death. At autopsy, macroscopic techniques fail to reach beyond superficial layers of degraded tissue to identify wound morphology that characterizes blunt-force gunshot, and sharp-force trauma. The postmortem damage imparted on tissue with pre-existing injuries, obstructs the external features of trauma. Exploring beyond charred and decayed superficial tissue, histo-morphological patterns of injury are still identifiable as shown in this thesis. With detailed observation to the pattern of tissue disruption- an understanding of the type of trauma imposed can be found. Tissue injuries are exaggerated by thermal effects of burning and degraded by the taphonomic effects. This work aims to explore histomorphological findings of such challenging samples. Together with bone toolmark analysis, the information obtained from tissue trauma morphology can be applied to further develop models that can aid in the identification of trauma type and the tools used to inflict it

Optical and colorimetrical characteristics of strained LiF crystals under X-ray irradiation

Here there were investigated the х-irradiation influence on the optical characteristics of LiF crystals and the colorimetric characteristics of optical radiation passing through crystals with different doses of irradiation. It was established that change of irradiation dose in the interval 0…1057 Р leads to reduce of absolute value of coordinates of the color and brightness of the radiation, passing through the crystal, but the color of the radiation thus remains constant.Досліджено вплив рентгенівського опромінення на оптичні характеристики кристалів LiF і колориметричні характеристики оптичного випромінювання, що проходить через кристали з різними дозами опромінення. Встановлено, що зміна дози опромінення в інтервалі 0…1057 Р призводить до зменшення за абсолютною величиною координат кольору і яскравості випромінювання, що проходить через кристал, але кольоровість випромінювання при цьому не змінюється.Исследовано влияние пластической деформации на оптические характеристики кристаллов LiF и колориметрические характеристики оптического излучения, проходящего через кристаллы с разными дозами облучения. Установлено, что изменение дозы облучения в интервале 0…1057 Р приводит к уменьшению по абсолютной величине координат цвета и яркости излучения, проходящего через кристалл, но цветность излучения при этом не изменяется

Multireference configuration interaction treatment of excited-state electron correlation in periodic systems: the band structure of trans-polyacetylene

A systematic method to account for electron correlation in periodic systems which can predict quantitatively correct band structures of non-conducting solids from first principles is presented. Using localized Hartree-Fock orbitals (both occupied and virtual ones), an effective Hamiltonian is built up whose matrix elements can easily be transferred from finite to infinite systems. To describe the correlation effects wave-function-based multireference configuration interaction (MRCI) calculations with singly and doubly excited configurations are performed. This way it is possible to generate, both, valence and conduction bands with all correlation effects taken into account. Trans-polyacetylene is chosen as a test system.Comment: 9 pages, 2 figures, submitted to Chem. Phys. Let