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Evi Honegger 《Theoretical chemistry accounts》1988,73(4):317-322
New formulae for the approximate computation of total molecular energies are developed based on ab initio calculations of n-alkanes. Their application to various kinds of molecules reveals that good expectation values for total molecular energies can be obtained by considering only the one-electron terms h
i and the nuclear repulsion energy. It is further shown that very good agreement with SCF total energies is obtained by a relationship which connects the total energy with the sum of inner-shell (core) orbital energies. The results turn out to be better than those obtained using Ruedenberg's approximation, which takes both inner-shell and valence-shell orbital energies into account. 相似文献
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The
algebra CCR (E) of the CCR depends sensitively on the choice of the one boson test-function space E. Here the unique extension of certain continuous states, resp. representations, to the extended CCR algebra CCR E corresponding to an enlarged test-function space E is studied. Various applications in statistical physics, QED, quantum optics, solid state physics, and quantum chemistry are pointed out. 相似文献
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Reinhard Honegger 《Letters in Mathematical Physics》1991,21(4):351-359
Recently, the finite temperature states of the spin-boson model were studied. Here with different techniques in the case of level-splitting zero, the explicit expressions for both the dynamics and the equilibrium states are derived, namely Trotter's product formula and analyticity methods from perturbation theory are used. 相似文献
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A closed, entirely quantum mechanical Josephson oscillator model is considered,
consisting of two superconductors in tunneling contact, which weakly interact
with the photon field. For each superconductor we use, for notational simplicity,
the BCS model in the strong coupling approximation and restrict ourselves
to Andersons quasi-spin formulation. The thermodynamic limit of the global (non-equilibrium)
dynamics is formulated for a large variety of states. It arises a generalization
of previously developed cocycle equations, connecting the collective behaviour
of the two superconductors with the photon field dynamics. In the physically
most interesting situations, where the two superconductors are in thermal
equilibrium (below the critical temperature) at voltage difference V, we show, that
for arbitrary initial states the outgoing multi-photon states are quantum optically
all-order coherent and constitute an almost monochromatic radiation of frequency
$ 2eV/\hbar $. Furthermore, we deduce in detail, how the collective behaviour of the superconductors
influences the collective (that are the optical) features of the emitted
microwave photons.
Communicated by Joel Feldman
submitted 14/02/03, accepted: 04/03/03 相似文献
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Rolf Bombach Josef Dannacher Evi Honegger Jean-Pierre Stadelmann Reinhard Neier 《Chemical physics》1983,82(3):459-470
The photoelectron spectrum of cyclopropanol has been determined and the first few bands have been assigned to the respective ionization processes. The dissociative photoionization of cyclopropanol and allyl alcohol has been studied by means of HeIα photoelectron—photoion coincidence spectroscopy. The breakdown diagrams of the two corresponding radical cations are practically indistinguishable within the entire energy range investigated (= 5 eV). This implies that extensive isomerizations to a single or to a mixture of common precursor structure(s) precede the dissociative processes. The currently available information on the structure of this reactant and, in particular, the role of other C3H6O+ isomers is discussed. The kinetic and thermodynamic aspects of the present results are outlined. Although three generations of daughter ions are involved, the relative importance of the different fragmentation pathways could be determined. The RRKM analysis of the coincidence data suggests that the formation of the ethylene cation by loss of a CO molecule from the parent ion hardly competes with the other four primary fragmentation reactions in the sense of the statistical theory of unimolecular reactions. 相似文献
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Evi Honegger Edgar Heilbronner Thomas Urbanek Hans-Dieter Martin 《Helvetica chimica acta》1985,68(1):23-38
The σ-orbital manifold of cubane 1 , as suggested by its PE spectrum, is divided into two sets separated by a 3 eV gap extending from ~ -10.5 eV to ~ -13.5 eV. Halogen substituents with np AO basis energies falling into this gap (e.g. Cl or Br) will, therefore, hyperconjugate appreciably with both sets. Interaction with the lower-lying set will lead to the usual destabilization (‘normal’ hyperconjugation), whereas interaction with the set above will necessarily lead to a ‘stabilization’ (‘inverted’ hyperconjugation). As a result the lone-pair ionization energies of Cl or Br substituted cubanes (derived from PE spectra) are much larger than naively expected for an alkyl halide containing as much as 8 C-atoms. In particular no significant shift of the e lone-pair bands in the PE spectra of 1,4-dichloro- and 1,4-dibromocubane can be detected with respect to the first ionization energies of the free atoms Cl and Br, or of HCl and HBr. 相似文献
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Zhu H Ahmidouch A Anklin H Arenhövel H Armstrong C Bernet C Boeglin W Breuer H Brindza P Brown D Bültmann S Carlini R Chant N Cowley A Crabb D Danagoulian S Day DB Eden T Ent R Farah Y Fatemi R Garrow K Harris C Hauger M Honegger A Jourdan J Kaufmann M Khandaker M Kubon G Lichtenstadt J Lindgren R Lourie R Lung A Mack D Malik S Markowitz P McFarlane K McKee P McNulty D Milanovich G Mitchell J Mkrtchyan H Mühlbauer M Petitjean T Prok Y Rohe D Rollinde E Rondon OA Roos P Sawafta R Sick I Smith C 《Physical review letters》2001,87(8):081801
We report the first measurement using a solid polarized target of the neutron electric form factor G(n)(E) via d-->(e-->,e(')n)p. G(n)(E) was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia ( 15ND3). The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility in quasifree kinematics with the target polarization perpendicular to the momentum transfer. The electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle segmented detector. We find G(n)(E) = 0.04632+/-0.00616(stat)+/-0.00341(syst) at Q2 = 0.495 (GeV/c)(2). 相似文献