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Particle integral function

Second-Order Integral Equations for Associating Fluids As mentioned above in Sec. II A, the second-order theory consists of simultaneous evaluation of the one-particle (density profile) and two-particle distribution functions. Consequently, the theory yields a much more detailed description of the interfacial phenomena. In the case of confined simple fluids, the PY2 and HNC2 approaches are able to describe surface phase transitions, such as wetting and layering transitions, in particular see, e.g.. Ref. 84. [Pg.186]

First we define the linear map that produces the densities from N-particle states. It is a map from the space of A -particle Trace Class operators into the space of complex valued absolute integrable functions of space-spin variables... [Pg.225]

In Section 8.4.2, we considered the problem of the reduced dynamics from a standard DFT approach, i.e., in terms of single-particle wave functions from which the (single-particle) probability density is obtained. However, one could also use an alternative description which arises from the field of decoherence. Here, in order to extract useful information about the system of interest, one usually computes its associated reduced density matrix by tracing the total density matrix p, (the subscript t here indicates time-dependence), over the environment degrees of freedom. In the configuration representation and for an environment constituted by N particles, the system reduced density matrix is obtained after integrating pt = T) (( over the 3N environment degrees of freedom, rk Nk, ... [Pg.116]

One big problem, which arises mainly in crystals with rather large unit cells, is the overlapping of reflections. This prevents an accurate measurement of the local integrated intensities of a large number of reflections. A solution to this problem can be the 2D pattern decomposition method, which is based on the same principles as in X-ray powder diffraction. This method takes into account the dependence of intensities on the particle orientation function and the size of microcrystals. It is therefore necessary to establish the mathematical formalism that describes the dififiaction pattern taking into account these parameters. [Pg.122]

If the TV-particle basis were a complete set of JV-electron functions, the use of the variational approach would introduce no error, because the true wave function could be expanded exactly in such a basis. However, such a basis would be of infinite dimension, creating practical difficulties. In practice, therefore, we must work with incomplete IV-particle basis sets. This is one of our major practical approximations. In addition, we have not addressed the question of how to construct the W-particle basis. There are no doubt many physically motivated possibilities, including functions that explicitly involve the interelectronic coordinates. However, any useful choice of function must allow for practical evaluation of the JV-electron integrals of Eq. 1.7 (and Eq. 1.8 if the functions are nonorthogonal). This rules out many of the physically motivated choices that are known, as well as many other possibilities. Almost universally, the iV-particle basis functions are taken as linear combinations of products of one-electron functions — orbitals. Such linear combinations are usually antisymmetrized to account for the permutational symmetry of the wave function, and may be spin- and symmetry-adapted, as discussed elsewhere ... [Pg.330]

Mode coupling theory of binary mixtures where the constituents are of rather different sizes is a challenging task, as we have already discussed while addressing the mass depenence of diffusion. In addition to the problem with proper formulation of mode coupling terms, there is an additional difficulty of the nonavailability of the equilibrium two-particle correlation functions The existing integral equation theories become unstable when the size ratio exceeds a certain (low) value, like 1.5 or so [195],... [Pg.213]

Following van der Waals and Platteeuw (1959, pp. 26ff) the individual particle partition function is related to the product of three factors (1) the cube of the de Broglie wavelength, (2) the internal partition function, and (3) the configurational triple integral, as... [Pg.274]

This expression could be found by integrating function (1.35) with respect to the co-ordinates of the particles of all the macromolecules apart from the particles of a chosen one.3 In this situation, one can use the results for ideal coil, so that one can write for the parameter... [Pg.16]

B(r, X) = XmB(r), where m n. Inserting the last form of the bridge function in Eq. (104) to achieve the integration yields the convenient form for the one-particle bridge function... [Pg.48]

ARPE5 measures the single-particle spectral function A(k,w), within the photoionization weight factor (w), and gives, on frequency integration the in-plane momentum (k) distribution, function... [Pg.282]

In this account we will review the structural and functional properties of the respiratory chain components, as they are known from studies with intact mitochondria, vesicles of the inner mitochondrial membrane (submitochondrial particles), or isolated complexes. The latter may additionally be reconstituted into liposomal membranes. To some extent we will also review the knowledge on the integrated functions of the respiratory chain with main emphasis on proton translocation and essential thermodynamic and kinetic properties. [Pg.51]

Wave functions (13) apply to any pair of coupled centrosymmetric protons, irrespective of the distance and of the magnitude of the coupling term. Quantum correlation arises exclusively from normal coordinates representing dynamics of indistinguishable particles. It has been proposed [Keen 2003] that quantum entanglement could be due to the overlap integral of the one-particle wave functions >Pi, (a o , ) for protons ... [Pg.518]

Another important air-quality parameter, visibility, is closely related to the aerosol extinction coefficient. The extinction coefficient, like the total mass, is an integral function of the particle size distribution. However, for urban pollution it tends to weight the contribution of material in the 0,1 - to I. O-pm size range most heavily (Chapter 5). There is a separate mass based U.S. EPA standard for non-health related effects such as visibility. [Pg.380]

From a practical point of view, however, it is clear that the procedure described above is highly nontrivial Apart from the necessity to deal with mixtures of n-l-1 components, the way to carry out the limit n — 0 in practice is by no means straightforward. One method to deal with these difficulties is the replica integral equation formalism, which we will introduce Section 7.5. However, before doing this we first introduce the key concepts of the replica integral equations, which are the two-particle correlation functions of the QA system. [Pg.348]

This is the Ornstein-Zernike equation. It is an exact integral equation relating the two 2-particle correlation functions li2(l,2) and C2(l,2). It is possible to motivate this equation form purely physical arguments the idea is to interpret the total correlation function li2(l,2) as the sum of all possible direct correlations, thus C2(l, 2) is termed the direct correlation function. We imagine that 112(1,2) is the sum of the direct correlation between 1 and 2 (that is 2(1,2)), and all chains of direct correlations via a third, fourth etc., particle. The weakness of this heuristic derivation is that we do not know how to write down an expression for 2(1,2). The great advantage of the formal... [Pg.462]

In Eq. (3.7.9) Hg is the matrix of particle-particle correlation functions for the reference system and has the same form as the matrix H used in the Rossky-Chiles reformulation of the CSL integral equation. The matrix p is also the same as that used by Rossky and Chiles. [Pg.496]


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See also in sourсe #XX -- [ Pg.422 ]




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