摘要:

A new efficient algorithm for solving hypernetted-chain (HNC) theories of the primitive model double layer is described. The new algorithm provides solutions of the HNC/MSA and HNC/HNC equations for 1 : 1 and 2 : 2 aqueous electrolytes for most conditions of physical interest. The HNC/HNC results, which are almost all new, are good (as compared with Monte Carlo results) for concentrated electrolytes but deteriorate at lower concentrations except at low surface charge densities. The HNC/HNC coion density profiles show spurious features similar to those previously reported in HNC calculations for bulk electrolytes. Ideas from density functional theory are used to suggest a possible explanation for the perversely good performance of the HNC/MSA equations.

ISSN:0026-8976    

DOI:10.1080/00268978500100401

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Using an effective mass hamiltonian approach developed in studies of energy transfer in molecular collisions, we derive a simple theory of vibrational energy exchange in adsorbed polyatomic molecules. As an application, the vibrational relaxation of CH3Cl and CD3Cl adsorbed on solid Ar is discussed, and the most important accepting modes in the energy relaxation of the ν4mode are predicted. Possibilities to study the problem experimentally are also discussed briefly.

ISSN:0026-8976    

DOI:10.1080/00268978500100411

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The lowest excited singlet and triplet states of the oxalyl halides, (COX)2withX= F, Cl, and Br, have been investigated at ˇ- 4 K by optical and ODMR spectroscopy. The observed excited states are assigned as the1, 3Au(nπ*) states of the planartransisomers. A partial reassignment of the ground state fundamentals is presented, based on the ODMR activities in the vibronically resolved emission spectra. Variations seen in the kinetic parameters and fine structure splittings of the3Austate in the series are interpreted in terms of oxygen- and halogen-centred spin-orbit interactions.

ISSN:0026-8976    

DOI:10.1080/00268978500100421

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A sensitivity analysis formalism is constructed for collinear reactive systems with multiple electronic potential energy surfaces. The work extends the sphere of application of sensitivity theory into the reactive domain. Expressions are obtained for the first order elementary sensitivity coefficients (i.e. partial derivatives) of both the reactive and non-reactive component elements of the scattering matrix with respect to an arbitrary system parameter. In the case of the non-reactive elements, the sensitivity coefficients involve essentially the piecewise integration of a function matrix containing the available solution of the scattering problem. The reactive sensitivity coefficients draw on both forward and backward propagated solutions. The paper concludes with a discussion of the scope and applicability of reactive sensitivity analysis.

ISSN:0026-8976    

DOI:10.1080/00268978500100431

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A uniform classicalSmatrix theory of bound-bound Franck-Condon factors is developed and applied to a model non-separable potential system with two degrees of freedom. Comparison with exact quantum results shows the method to be substantially more accurate than the Heller frozen gaussian approach, although the latter gives acceptable accuracy for many purposes and also has advantages of flexibility and ease of operation.

ISSN:0026-8976    

DOI:10.1080/00268978500100441

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The method of molecular dynamics at fixed pressure and/or temperature is adapted to rigid or partly rigid molecular systems with geometrical constraints using the cartesian coordinate approach. Both isotropic and anisotropic volume fluctuations, allowing for shape variation, are considered. The simulation of a benzene crystal at zero pressure and various temperatures is given as an illustration.

ISSN:0026-8976    

DOI:10.1080/00268978500100451

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Rate constant calculations are reported for the gas-phase reactions of HCN with H-, D-and H+3ions. The technique used in the computations involves a combination of adiabatic capture and centrifugal sudden approximations. The convergence of the calculated cross sections, with respect to rotational basis functions, is improved by use of localized functions of the form exp (Acos θ), where θ is the atom-molecule orientation angle. These functions localize the hindered rotational wavefunctions about the collinear configuration, which is appropriate for the collisions of ions with molecules possessing dipole moments. Excellent agreement with experimental room temperature rate constants is obtained. The theory predicts sharply increasing rate constants as the temperature decreases, and this is related to the strong sensitivity of rotationally selected rate constants to the initial rotational state.

ISSN:0026-8976    

DOI:10.1080/00268978500100461

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

The role of symmetry in the non-radiative relaxation of Cr3+complex ions is considered by evaluating the relative rates of the4T1g→4A2gnon-radiative relaxation in the cubic Cr(NH3)3+6ion. By using a linear ligator approximation for the dynamics of the complex ion and a crystal field representation of the perturbation of the metald-orbitals by the motion of the ligand ‘lone pair’ orbital and the hydrogen atoms, it is shown that theT1gligand rocking motion is rather ineffective in relaxing the4T2gstate to the4A2gground state. The importance of this in accounting for the luminescence ofd3ions is considered.

ISSN:0026-8976    

DOI:10.1080/00268978500100471

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

We derive expressions for the isothermal response ofN-particle systems to a mechanical perturbation. Thermostating is achieved using gaussian isothermal equations of motion. Our theory is ergodically consistent in the sense that ensemble averages over the initial phases of the system are equivalent to time averages of the isothermal steady state response.

ISSN:0026-8976    

DOI:10.1080/00268978500100481

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

A projection operator technique is applied to study the influence of interaction-induced mechanisms on density fluctuation-induced isotropic (DFIILS) and orientation fluctuation-induced anisotropic (OFIALS) light scattering. Analytical formulae for the integrated intensity of purely interaction-induced isotropic (PIIILS) and purely interaction-induced anisotropic (PIIALS) light scattering are derived. The integrated intensity of PIIILS as well as PIIALS is found in the form of the difference of ‘square’ and ‘cross’ contributions. Both terms are calculated numerically for liquid N2and CO2within the first order approximation of the dipole-induced dipole (DID) model. The same order of magnitude is obtained for the ‘square’ and ‘cross’ contributions.

ISSN:0026-8976    

DOI:10.1080/00268978500100491

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor