摘要:

The vapour-phase Raman spectra of the molecules POF3, POCl3, VOF3, VOCl3, PSCl3and FClO3have been recorded in sealed tubes at 22–230°C, and accurate values for the fundamentals are reported. The Raman band contours of theespecies fundamentals have been analysed to yield Coriolis constants from whichespecies force constants have been calculated. Raman and infra-red-based Coriolis constants are compared. Values for various thermodynamic functions of the molecules have been evaluated from the new values for the fundamentals, and from the most recent structural parameters.

ISSN:0026-8976    

DOI:10.1080/00268977400102871

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

In liquids, the autocorrelation function for angular velocity, <ωx(t)ωx(0)>, and the corresponding correlation time,τω, where

ISSN:0026-8976    

DOI:10.1080/00268977400102881

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A sum rule for the total inelastic cross section of H2+colliding with fast charged particles is evaluated in the first Born approximation using the clamped nuclei [Born-Oppenheimer (B.O.)] wave function and the adiabatic wave function. The vibrational correction to this cross section is of almost the same magnitude for both wave functions, and its value is about 5 per cent of the total. The parameters for the sum rule which depend upon the internuclear distanceRare evaluated fromR=1·4a0toR=2·6a0for the B.O. wave function. These parameters are found to have better asymptotic behaviour for smallRthan for largeR.

ISSN:0026-8976    

DOI:10.1080/00268977400102891

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The diagrammatic method of Prigogine and co-workers is applied to the problem of the derivation of the kinetic equation for adsorbed gases. The model of a two-dimensional rarified gas is presented and the general statistical-mechanical description of this model is elaborated. The appropriate classes of diagrams are summed for the case of homogeneous systems leading to the kinetic equation with two dissipative terms: (a) the Boltzmann collision integral, (b) the Fokker-Planck term with a velocity-dependent friction coefficient. The extension of the theory to inhomogeneous systems is accomplished using the concept of pseudodiagonal diagrams. A short comparison of the result obtained with a similar theory for a simple liquid and the theory of a particle coupled to the crystal lattice is also included.

ISSN:0026-8976    

DOI:10.1080/00268977400102901

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The electronic wave function of the ion cluster BeH+H2has been calculated for a series of nuclear arrangements with the aid of the IEPA-PNO method (Independent Electron Pair Approximation using Pair Natural Orbitals) which included valence shell correlation. The equilibrium geometry of BeH3+hasC2νsymmetry. The four nuclei lie in a plane; the H2molecule is perpendicular to the BeH+ion and 1·60 Å in front of the Be atom. The stability of the cluster with respect to dissociation into BeH+and H2is 24·7 kcal/mole. Perturbation theory has been used in order to get an understanding of the interaction of BeH+and H2. This attempt however was successful only for larger intermolecular distances (R> 5 Å).

ISSN:0026-8976    

DOI:10.1080/00268977400102911

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

A general microscopic theory of polarized light scattering from a dilute polymer solution is presented. Interactions between the subunits of the polymer are explicitly allowed, so that multiple scattering within the polymer is recognized. The incident and observed light may have any polarization. A formula for the light scattering from a collection of oriented polymer molecules is given, and then its orientation average is taken so that it applies to a dilute solution of the polymer. The averaging process results in a remarkable simplification of the scattering equation, terminating an infinite series exactly after five terms. The only remaining infinite series may be accurately truncated after two terms for polymers in the size range of biological interest, producing a closed expression for the scattered intensity. It is concluded that light scattering from biological polymers is governed by no more than eight important parameters (three zeroth order and five first order), even in the case of resonance Raman scattering. Much of the calculation is carried out in spherical tensor representation, but the final formulae are given in the standard Cartesian vector notation.

ISSN:0026-8976    

DOI:10.1080/00268977400102921

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

In order to study the relation between chemical potentials and reactivity we divide the interaction region into physically decisive potential ‘boxes’. Each box is considered to be a small interaction region for a virtual chemical reaction with corresponding virtual transition probability amplitudes. These amplitudes are linked together and superimposed in a ‘state path sum’ which relates local potential properties with exact reaction probabilities. The state path sum is carried out by the supermatrix technique of the statistical theory of chain molecules.

ISSN:0026-8976    

DOI:10.1080/00268977400102931

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

The use of the nephelauxetic ratio for the calculation of percent covalency is examined. Values ofFkandEkobtained from four parameter fits (e.g.F2,F4,F6and ζ4f) neglecting configuration interaction for Pr3+in various host lattices are compared to those of the free ion. By including the effects of 4f-ligand overlap one can account for the empirically obtained order of sensitivity to the environment forFk:F2>F4>F6and forEk:E2>E3>E1. The results further indicate that by using the nephelauxetic effect and the relationshipb= (1 - β)/2 one is likely to overestimate the degree of covalency of a complex.

ISSN:0026-8976    

DOI:10.1080/00268977400102941

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

摘要:

Coupling constants between CH3or CF3groups and a nucleus elsewhere in the molecule are averages over internal rotation. The probability distribution functions of the relevant dihedral angles have been calculated for temperatures 173 and 373 K, and combining these with calculations of the angular dependence of the coupling constants, enables us to predict the temperature dependences. It is predicted that3JHFin ethyl fluoride is independent of temperature, but3JFFin CF3CFH2and CF3CFO and4JFFin CF3CF=CF2are predicted to show appreciable changes over 200 K.

ISSN:0026-8976    

DOI:10.1080/00268977400102951

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor

ISSN:0026-8976    

DOI:10.1080/00268977400102961

出版商:Taylor & Francis Group    

年代:1974

数据来源: Taylor