A multiconfigurational time-dependent Hartree-Fock method for excited electronic states. I. General formalism and application to open-shell states

The solution of the time-dependent Schrodinger equation for systems of interacting electrons is generally a prohibitive task, for which approximate methods are necessary. Popular approaches, such as the time-dependent Hartree-Fock (TDHF) approximation and time-dependent density functional theory (TDDFT), are essentially single-configurational schemes. TDHF is by construction incapable of fully accounting for the excited character of the electronic states involved in many physical processes of interest; TDDFT, although exact in principle, is limited by the currently available exchange-correlation functionals. On the other hand, multiconfigurational methods, such as the multiconfigurational time-dependent Hartree-Fock (MCTDHF) approach, provide an accurate description of the excited states and can be systematically improved. However, the computational cost becomes prohibitive as the number of degrees of freedom increases, and thus, at present, the MCTDHF method is only practical for few-electron systems. In this work, we propose an alternative approach which effectively establishes a compromise between efficiency and accuracy, by retaining the smallest possible number of configurations that catches the essential features of the electronic wavefunction. Based on a time-dependent variational principle, we derive the MCTDHF working equation for a multiconfigurational expansion with fixed coefficients and specialise to the case of general open-shell states, which are relevant for many physical processes of interest. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3600397]

The calculation of accurate normal coordinates I: general theory, and application to methane

The calculation of accurate and reliable vibrational potential functions and normal co-ordinates is discussed, for such simple polyatomic molecules as it may be possible. Such calculations should be corrected for the effects of anharmonicity and of resonance interactions between the vibrational states, and should be fitted to all the available information on all isotopic species: particularly the vibrational frequencies, Coriolis zeta constants and centrifugal distortion constants. The difficulties of making these corrections, and of making use of the observed data are reviewed. A programme for the Ferranti Mercury Computer is described by means of which harmonic vibration frequencies and normal co-ordinate vectors, zeta factors and centrifugal distortion constants can be calculated, from a given force field and from given G-matrix elements, etc. The programme has been used on up to 5 × 5 secular equations for which a single calculation and output of results takes approximately l min; it can readily be extended to larger determinants. The best methods of using such a programme and the possibility of reversing the direction of calculation are discussed. The methods are applied to calculating the best possible vibrational potential function for the methane molecule, making use of all the observed data.

Fragm. lat. I 34 - Decretum, L. XIX (Corrector)

Trägerband: "Relation der Herrn Deputirten der Statt Franckfurt in Sachen Wedige contra Franckfurt ./. Commissionis so abgelegt worden ao. 1657 den 28 Julii...; Tom.spec. et ultimus"; Vorbesitzer: Stadtarchiv Frankfurt am Main

Fábula macarrónica ó consulta que han tingut el Rat Penal de Valencia en lo Lleó dels Blanquers, sobre cèrta disposició que juçgá convenient, pera mes solemniçar el Arribo de les Magestats [Texto impreso]

Contiene: Bando General quel molt ilustre Rat Penat de Valencia dirig a tots los pobles de la sehua horta

Bibliografía especializada sobre Traducción e Interpretación: la revista MonTI (Universidades de Alicante, Jaume I y València) (2009-2015)

Este artículo bibliográfico propone una panorámica de MonTI (Monografías de Traducción e Interpretación), una revista académica anual nacida en 2009 y publicada conjuntamente por las tres universidades públicas que ofrecen un grado en Traducción e Interpretación en la Comunidad Autónoma Valenciana.

Catalogue of the scientific books in the library of the Royal Society of New South Wales. Part I. General catalogue.

Cover-title.

Safe driving knowledge dissemination and testing techniques. Volume I. General findings. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Memoria, é sea suscinta historia de la preñez extra-uterina observada en Joaquina Serrate, en el hospital Real y General de Ntra. Sra. de Gracia de Zaragoza /

Mode of access: Internet.

The natural method of cureing the diseases of the body and the disorders of the mind, depending on the body : in three parts, Part I. General reflections ... Part II. The means and method for preserving life and faculties ..., Part III. Reflections on the nature and cure of particular chronical distempers /

Mode of access: Internet.