Spectroscopy of Molecualr Crystals: A Bibliography for 1975

Abstract

Our previous thermodynamical approach was reexamined to study phase transition of anion radical salts, [(C₆H₅)₃PCH₃]⁺ _{1 ? x}[(C₆H₅)₃AsCH₃]⁺ _x(TCNQ)^? ₂,(0≤x≤1). The mechanism of the phase transition of the solid solution at 1 atm pressure was confirmed to be αy [(C₆H₅)₃PCH₃]⁺ _{1 ? x}[(C₆H₅)₃AsCH₃]⁺ _x(TCNQ)^? ₂,(0≤x≤1) βy, and the volume change assoiated with the phase transition was estimated to be ΔV =-1.3 (1-x) cm³/mol.     

Current-voltage characteristics of a Schottky diode under conditions of a current disturbance of the distribution function

The effect of the distortion of the equilibrium electron distribution function (due to the removal of electrons) in a semiconductor on the rectifying properties of a diode with a Schottky barrier is studied for an arbitrary (spherically symmetric) dispersion law. Specific calculations and an experiment are carried out for an electronic gallium arsenide-nickel contact.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 32–38, April, 1986.     

Computational chemistry of the silicon nitride surface. 2. Binary hydroxylamine complexes. Geometry and bond energies

In order to study the silicon nitride surface it is interesting to consider hydrogen-bonded complexes with hydroxyl and amine key groups (OH...O, OH...N, NH...O, and NH...N). To investigate the behavior of the above bonds, we considered the water, ammonia, and hydroxylamine dimers and the binary hydroxylamine complexes with water and ammonia. The results of this work are compared with the data obtained by an ab initio method. Russian University of Peoples' Frienfship. Translated fromZhurnal Strukturnoi Khimii Vol. 37, No. 1, pp. 29–47, January–February, 1996. Translated by I. Izvekova     

Vibrations of dispersed silicas: A comparative

Four families of disperse amorphous silica representing different solid species modifications have been studied by inelastic neutron scattering at 10, 80 and 290 K. Doubly amplitude-weighted density of vibrational states (AWDS) have been obtained from the experimental time-of-flight spectra.     

High‐spin silicon fullerene Si60 and its oligomers

High‐spin states of the Si₆₀ fullerene and its oligomers are considered semiempirically by using sequential and parallel implementations of the AM1 codes. The states are energetically favorable and nearly degenerated over triplet, quintet, and septet spins. All atoms of the Si₆₀ fullerene are in sp³‐configuration, which is supported by atomic spin density in addition to electron density, the latter to be responsible for the formation of chemical bonds. Spotted distribution of spin density over atoms provides molecular magnetism of the molecule. A similar picture is disclosed for oligomers {Si₆₀}_n with n up to 8, which according to computational results should be magnetic with a fractal‐like distribution of spin density over atoms. Opposite the latter, composites Si₆₀C₆₀ and Si₆₀H₆₀ behave conventionally and are nonmagnetic. A way of the Si₆₀ fullerene synthesizing is suggested via the above composite product as intermediates. The considered oligomers are proposed as a model of silicon nanofibers observed recently. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002     

Spectra and structure for Bi0-BiCl3-Li,K/Cl

Raman-scattering, electronic-absorption, and ESR spectra have been used to determine the states of bismuth and the structures of the compounds formed in molten chloride systems; it is found that BiCl₄ ^– with T_d symmetry are formed in BiCl₃-Li, K/Cl_eu melts, while a Bi⁰-BiCl₃-Li, K/Cl_eu melt produces the BiCl₄ ^– BiCl₃ + Cl^–; BiCl₃ + Bi⁰ Bi₂Cl₃ equilibria with the formation of Cl^– the quasitetrahedral ion in the second stage, which has a metal-bond and a single unpaired electron.Institute for General and Inorganic Chemistry, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 3, pp. 311–315, May–June, 1991. Original article submitted September 12, 1988.     

Vibrational spectroscopy of dispersed silica: Aerosil

Conclusions A complex experiment has been carried out to examine the vibrational spectrum of Aerosil, and it has been found that the silanol group is the main active center of this type of dispersed silica. This fact conforms well with the previously advanced supposition that the structure of the core of silica is of a closed type in this case.The experimentally measured vibrational spectrum of the adsorbed water is practically completely described by a model in which one silanol center reacts with a water cluster. This agrees with the fact that chemical hydrophobic reactions take place on the surface of the usual commercial, i.e.,wet Aerosil. Since water is adsorbed as a cluster around one center, then in the presence of the usual 2. wt. % of water, a large part of the surface will be free of water and available for other reactions.It is natural that the above-considered simple models do not permit explanation of all the details of the observed spectra and a large amount of work will have to be carried out with more complicated models.Patrice Lumumba Peoples's Friendship University, Institute of Surface Chemistry, Ukrainian Academy of Sciences. Joint Institute of Nuclear Research. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 4, pp. 66–75, July–August, 1992.     

Computational modeling of amorphous silica. 2. Modeling the initial structures. Aerosil

A qualitative algorithm for constructing large clusters of aerosil model structures is used. According to this algorithm and the classification of amorphous silicas, aerosil is classified with tectosilicas, which are characterized by close packing of silicon-oxygen tetrahedra. Two quantitative algorithms for constructing large close-packed clusters are proposed. The structures of the clusters having from 10 to 24 silicon atoms, completely optimized by quantum chemical methods, were obtained. Small, medium, and large clusters for modeling the local and collective properties of atomic and functional group packing in the aerosil structure are distinguished. Institute of Surface Chemistry, Ukrainian Academy of Sciences. Russian University of Peoples' Friendship. Translated fromZhurnal Struktumoi Khimii, Vol. 35, No. 3, pp. 16–26, May–June, 1994. Translated by O. Kharlamova     

Computer modeling of assembly of atoms in an electric field

A computer modeling of events that occurred under the scanning tunneling microscope (STM ) tip was considered from a chemical standpoint. The DYQUAMOD, semiempirical dynamical-quantum chemical program system, which well manifested itself in a quantitative studying of nano-sized objects, was transformed into the DYQUAFIELD program system involving an external electrostatic field. The fields of changeable configurations were simulated by a set of up to 200 point charges. Atomic system modeling was focused on obtaining local electron density (LED ) as well as on the object chemical transformations caused by the field. This article presents the results of simulating LED of differently originated graphite films, of a field action on a set of stable molecules, and of an irreversible in-field reconstruction of the diamondlike film surface, which demonstrates a possible nano-sized memory element creation. © 1996 John Wiley & Sons, Inc.     

环形区域上Zernike模式法波前重构

 针对激光技术领域常见的环形激光光束,利用圆域Zernike多项式和环域Zernike多项式进行模式法波前重构,结果显示,如果环形激光光束波前相位畸变主要由低空间频率成分组成,则可以直接利用圆域Zernike多项式进行波前重构;如果环形激光光束波前相位畸变含有较多的高阶频率成分,则利用环域Zernike多项式进行波前重构。