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Energy expression propagator form

This expression is derived as the Fourier transform of a time-dependent one-particle autocorrelation function (26) (i.e. propagator), and cast in matrix form G(co) over a suitable molecular orbital (e.g. HF) basis, by means of the related set of one-electron creation (ai" ") and annihilation (aj) operators. In this equation, the sums over m and p run over all the states of the (N-1)- and (N+l)-electron system, l P > and I P " respectively. Eq and e[ represent the energy of the... [Pg.79]

As seen from (3.7), the closed paths with x(t0) = x(0) fully determine the energy spectrum of the system. The propagator K, when expressed in terms of the energy eigenfunctions n), has the form... [Pg.56]

The parameters governing crack propagation have been proposed by Sih and Madenci [8] with the strain energy density theory. The strain energy density function, d Wld V, in front of the crack tip has been expressed in the form... [Pg.647]

The excitation energies and transition moments of MCRPA can be determined as in RPA. Except for the dimensions of the A and B matrices and a different metric matrix (S, A) the propagators in MCRPA and RPA have the same form and we can thus express (P Q e in Eq. (116) in a spectral form using the transformations described in Eqs (102)-(105). The solution of the eigenvalue problem that arises has to be handled a little differently due to the non-imit metric matrix (see e.g. Oddershede et al, 1984, Appendix A). [Pg.225]

Here, as usual, ran = Vai — rai, final states of a system, i.e., the total level width is represented as sum of the partial contributions, connected with radiative decay into the concrete final states of a system. These contributions are proportional to the probabilities of the corresponding transitions. Naturally, the form of operator in (10) is determined by a gauge of the photon propagator (look discussion in Ref. [26]). In the zeroth approximation, the dependence f, on the nuclear and electron coordinates (/ n, l e(h)) is factorized ( eN). Therefore, the combined electron (hole)-nuclear one-photon transitions occur as each of the operators Tn and Te in (10) contains the combination of the nuclear and electron variables. After factorization and some transformations, the expression (10) can be presented in the following form ... [Pg.223]

More direct measures of interface debonding energy are provided by the pull-out or push-out tests shown in Fig. 16.26. When a tensile force is applied to a fiber to extract it from its composite matrix, an interface crack eventually starts to run along the fiber. It is obvious from a simple fracture mechanics argument that the stress on the fiber to propagate the crack, assuming a very compliant matrix, must be given by an expression of the form... [Pg.403]

To ensure the propagation, an exchange of capacitive and inductive energies is necessary this requires closing circuit for forming a loop, in other words, an oscillator. This is expressed by the nullity of the sum of pressure fields ... [Pg.371]


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