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Normal-order sequence extended

Extended normal-order sequence of operator strings 201... [Pg.177]

If applied to the reference state normal order enables us immediately to recognize those terms which survive in the computation of the vacuum amplitudes. The same applies for any model function and, hence, for real multidimensional model spaces, if a proper normal-order sequence is defined for all the particle-hole creation and annihilation operators from the four classes of orbitals (i)-(iv) in Subsection 3.4. In addition to the specification of a proper set of indices for the physical operators, such as the effective Hamiltonian or any other one- or two-particle operator, however, the definition and classification of the model-space functions now plays a crucial role. In order to deal properly with the model-spaces of open-shell systems, an unique set of indices is required, in particular, for identifying the operator strings of the model-space functions (a)< and d )p, respectively. Apart from the particle and hole states (with regard to the many-electron vacuum), we therefore need a clear and simple distinction between different classes of creation and annihilation operators. For this reason, it is convenient for the derivation of open-shell expansions to specify a (so-called) extended normal-order sequence. Six different types of orbitals have to be distinguished hereby in order to reflect not only the classification of the core, core-valence,... orbitals, following our discussion in Subsection 3.4, but also the range of summation which is associated with these orbitals. While some of the indices refer a class of orbitals as a whole, others are just used to indicate a particular core-valence or valence orbital, respectively. [Pg.201]

With this definition of the orbital indices, we now say that any (given) string of creation and annihilation operators obeys an extended normal-order sequence,... [Pg.202]

In fact, the definition of the extended normal-order sequence (50) is very crucial to our implementation of the GOLDSTONE program. Therefore, in order to make this convention more transparent for the reader, let us consider the effective one-particle part of the operator (47), F = /). Using the definitions of the... [Pg.202]

Brings an operator expression into normal-order i.e. into an extended normal-order-sequence as defined in Eq. (50). [Pg.208]

Evaluation of the operator products as they occur either on the rhs of fhe Bloch Eq. (23) or in fhe definifion of fhe effective operators (15) and (49). The aim of this step is to bring all the creation and annihilation operators (in each term of the expansions) into the extended normal-order form (50). The resulf is a sequence of normal-ordered operator ferms (briefly referred to as Feynman-Goldstone diagrams). [Pg.204]

Ito has also extended this type of photochemistry to the electron-beam-induced catalytic acidolysis of acid-labile main chain acetal linkages in polyphthaldehyde. These polymers, like the poly(2-methylpentene-l-suIfone) (PMPS) sensitizer in NPR resist described earlier have ceiling temperatures on the order of -40 °C. As normally used, the polyaldehydes are end-capped by acylation or alkylation and are thus quite stable. The main chain bonds are very sensitive to acid-catalyzed cleavage which in turn allows the whole chain to revert to monomer in an unzipping sequence similar to that occuring in irradiated PMPS. Irradiation of polyphthaldehyde containing 10% of a suitable sensitizer such as triphenylsulfonium hexafluoroarsenate with either deep UV... [Pg.107]

For the normal ground states of molecules, the simplest route to choosing a suitable extended set of zero-order orbitals la Hartree-Fock sea is to invoke the sequence of the shell model for the low-lying molecular orbitals in conjunction with the DN-D. Indeed, doing just that, together with the usual trial computations, in 1970 Das and Wahl [85] produced the first reliable results from MCHF calculations on the FES of the... [Pg.70]

This is illustrated in Fig. 9. The 2D spectra refer to quadrupole echo sequences and characterize two possible reorientation mechanisms of a methyl group (three-site jumps vs continuous diffusion). Drastic spectral differences are observed. Ajqjarratly, these 2D relaxation spectra sensitively indicate the type of motion. The same is true for the corresponding normalized contour dots (see Fig. 9). We note that similar 2D spectra can be obtained from inversion recovery or Jeener-Broekaert sequences (see Fig. 6) [68]. Thus, by applying this 2D technique to different pulse sequoic, the various motions can be differentiated over an extremely wide dynamic range, extending from the fast-rotational to the ultraslow motional re me. Sin<% the different motions (see Fig. 4) modulate different kinds of molecular order (see Fig 3) these orders can be differentiated, likewise. [Pg.11]

There is independence of the computation rules. But a fairness condition requires that no atom be indefinitely ignored by NFL The completeness proof of extended execution [Kanamori 86] states that every logical consequence is provable by a so-called normalized derivation, in which a sequence of NFI inferences precedes a sequence of DCI inferences, which in turn precedes a sequence of Sim inferences. Hence the idea of a priority ordering between the inference rules, namely NFf > DCI > Sim. [Pg.119]

Pulsed sequences are used to decouple the various contributions to the nuclear magnetic interaction. Since most spectrometers operate at frequencies of the order of several hundred megahertz, the timescale of the fluctuations observed are of the order of 10 to 10 s and hence are dominated by the segmental motions of the polymer. However, using special pulse sequences, these timescales can be extended to 10 s, when the influence of normal modes becomes evident. Such pulsed measurements are usually made at a single frequency, so it is difficult to obtain a meaningful picture of a distribution of relaxation processes. [Pg.206]

Normal mode calculations have been routinely applied to nucleic acids in order to interpret spectroscopic and neutron diffraction data and to understand the impact of allomorphic form, base sequence and environment on harmonic dynamics. The lowest frequency modes of duplex DNA (which extend down to roughly 20 cm , corresponding to characteristic times of 20 ps) are responsible for main component... [Pg.1916]

In this subsection we shall consider the situation in which we have extended gating service with no possibilities for overtime. During the production interval of a type we can work on any order of this type, but not on orders of another type. If somewhere during the production interval there are no (more) orders of the type, we must wait until the interval is finished or until new orders arrive. Jobs that are not finished by the end of the production interval have to wait until the next production opportunity. In the next production interval the work on these orders will be continued, so no extra work outside the normal working hours will be done. The set-up will be done just before the production interval. We are especially interested in the average delivery times for the different types. Therefore we must make some assumptions about the demand and service time distribution and about the sequence set S, which may enable us to calculate the delivery times. [Pg.23]


See other pages where Normal-order sequence extended is mentioned: [Pg.196]    [Pg.95]    [Pg.95]    [Pg.154]    [Pg.96]    [Pg.54]    [Pg.688]    [Pg.553]    [Pg.72]    [Pg.36]    [Pg.357]    [Pg.1823]    [Pg.228]    [Pg.279]    [Pg.284]    [Pg.107]    [Pg.154]    [Pg.9]    [Pg.153]    [Pg.697]    [Pg.228]   
See also in sourсe #XX -- [ Pg.201 ]




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Normal-order sequence

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