Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Function operator corresponding

C14-0120. In a system operating without any restrictions, heat is not a state function. However, heat flow describes a state function change under certain restricted conditions. For each of the following conditions, identify the state function that corresponds to heat flow (a) gy, (b) qp and (c) qp. [Pg.1042]

Instead of a conjunction of preconditions, as used by the STRIPS and conditional operators, the functional operator has a set of conjunctions of preconditions (Fig. 2c). Each element in the set describes some possible situation that might exist before the operator is applied. For each element of the set of preconditions, there is a corresponding element in the set of postconditions. The functional operator is a more flexible model than the STRIPS or conditional operators. It comes closer to the modeling needs for the synthesis of operating procedures for chemical processes, but as we will see in the next section, we need to introduce additional aspects in order to capture the network-like structure of chemical processes. [Pg.48]

The first theoretical handling of the weak R-T combined with the spin-orbit coupling was carried out by Pople [71]. It represents a generalization of the perturbative approaches by Renner and PL-H. The basis functions are assumed as products of (42) with the eigenfunctions of the spin operator corresponding to values X = 1/2. The spin-orbit contribution to the model Hamiltonian was taken in the phenomenological form (16). It was assumed that both interactions are small compared to the bending vibrational frequency and that both the... [Pg.617]

Values of the Intrinsic Bindii Constants (in lit/mol). Correlation Functions, and Corresponding Free Energies (in kcal/mol) for Binding of the A, Repressor to the Left Operator... [Pg.187]

In addition to operators corresponding to each physically measurable quantity, quantum mechanics describes the state of the system in terms of a wavefunction F that is a function of the coordinates qj and of tune t. The function l F/(qj,t)l2 = P P gives the probability density for observing the coordinates at the values qj at time t. For a many-particle system such as the H2O molecule, the wavefunction depends on many coordinates. For the H2O example, it depends on the x, y, and z (or r,0, and < )) coordinates of the ten... [Pg.9]

The postulates and theorems of quantum mechanics form the rigorous foundation for the prediction of observable chemical properties from first principles. Expressed somewhat loosely, the fundamental postulates of quantum mechanics assert dial microscopic systems are described by wave functions diat completely characterize all of die physical properties of the system. In particular, there aie quantum mechanical operators corresponding to each physical observable that, when applied to the wave function, allow one to predict the probability of finding the system to exhibit a particular value or range of values (scalar, vector. [Pg.4]

First, one has to decide what the quantum-mechanical translation is of the autocorrelation function, Eq. (4). Let Q be the operator corresponding to the physical quantity q, and let... [Pg.73]

If A is the operator corresponding to the physical property A, then any measurement of the property A in any quantum-mechanical system must give a result that is one of the eigenvalues of the operator A. The eigenvalues a( and the eigenfunctions [Pg.7]

We shall obtain a new type of a relativistic wave function if we use in Eq. (2.15) expression (2.18) instead of (2.16). However, usually in this case / is chosen to equal —1/2. Such a form leads to simpler phase multipliers for some quantities of the corresponding mathematical apparatus, but does not affect the matrix elements of the operators corresponding to physical quantities. [Pg.15]

When constructing many-electron wave functions it is necessary to ensure their antisymmetry under permutation of any pair of coordinates. Having introduced the concepts of the CFP and unit tensors, Racah [22, 23] laid the foundations of the tensorial approach to the problem of constructing antisymmetric wave functions and finding matrix elements of operators corresponding to physical quantities. [Pg.110]

The method of CFP is an elegant tool for the construction of wave functions of many-electron systems and the establishment of expressions for matrix elements of operators corresponding to physical quantities. Its major drawback is the need for numerical tables of CFP, normally computed by the recurrence method, and the presence in the matrix elements of multiple sums with respect to quantum numbers of states that are not involved directly in the physical problem under consideration. An essential breakthrough in this respect may be finding algebraic expressions for the CFP and for the matrix elements of the operators of physical quantities. For the latter, in a number of special cases, this can be done using the eigenvalues of the Casimir operators [90], however, it would be better to have sufficiently simple but universal formulas for the CFP themselves. [Pg.175]

The energy spectrum of atoms and ions with j j coupling can be found using the relativistic Hamiltonian of iV-electron atoms (2.1)-(2.7). Its irreducible tensorial form is presented in Chapter 19. The relativistic one-electron wave functions are four-component spinors (2.15). They are the eigenfunctions of the total angular momentum operator for the electron and are used to determine one-electron and two-electron matrix elements of relativistic interaction operators. These matrix elements, in the representation of occupation numbers, are the parameters that enter into the expansions of the operators corresponding to physical quantities (see general expressions (13.22) and (13.23)). [Pg.273]

The quantity 8Ia is the linearized collision operator corresponding to (4.62). The subscript 0 in the second term means that the operator acts only on the function fa and not on the delta distribution. The contribution Aap in (5.14) is determined by /a/3, that is by the large-scale fluctuations. We consider only the approximation that Aa/ is equal to zero. [Pg.250]

Figure 3.6. This figure shows that the effect on dxy of the function operator R, which corresponds to the symmetry operator R = R(n/2 z), is just as if the contours of the function had been rotated by R. Figure 3.6. This figure shows that the effect on dxy of the function operator R, which corresponds to the symmetry operator R = R(n/2 z), is just as if the contours of the function had been rotated by R.
In eq. (12), R(o) is the function operator that corresponds to the (2-D) configuration-space symmetry operator R(o). In eq. (13), /3 is the infinitesimal generator of rotations about z (eq. (8)) exp(i /3) is the operator [/do)] in accordance with the general prescription eq. (3.5.7). Notice that a positive sign inside the exponential in eq. (2) would also satisfy the commutation relations (CRs), but the sign was chosen to be negative in order that /3 could be identified with the angular momentum about z, eq. (6). [Pg.184]

The commutators, eqs. (4) and (5), are derived in three different ways, firstly from eq. (11.3.9) and then in Exercises (11.4-1) and (11.4-2) and Problem 11.1. Note that It, /2, and /3 are components of the symmetry operator (infinitesimal generator) I which acts on vectors in configuration space. Concurrently with the application of a symmetry operator to configuration space, all functions fir, 0, p) are transformed by the corresponding function operator. Therefore, the corresponding commutators for the function operators are... [Pg.188]

All the above relations, eqs. (7)—(15), hold for the corresponding function operators, the presence (or absence) of the carat sign serving to indicate that the operator operates on functions (or on configuration space). The effect on a vector r of a rotation through a small angle [Pg.189]

Using the Fourier-Wigner transform, we can calculate the explicit expressions for position and momentum operators, corresponding to eqs.(10). The transformation is applied to the functions X,/>( ) and hDjip(0 t° obtain the results... [Pg.444]

The prime on the delta function indicates differentiation with respect to the variable given in the subscript. The prime on the coordinate is just another coordinate value, different from the coordinate without a prime. This prime should not be confused with the prime on the delta function. The operator corresponding to a dependent variable ui(q,p) is given by a Hermitian operator Cl(q,p) = u> q —> q,p —> p). At the end of this section the complete expression for the relations with all coordinates is given. For brevity of notation, we usually only include the coordinate of interest, as in Eqs(F.8) and (F.9). [Pg.345]

The p yR < p , > operator corresponds to the energy contribution that we previously called Uee. This operator changes during the iterative solution of the equation. VR, is said to be the response function of the reaction potential. It is important to note that this term induces a nonlinear character to Equation (1.107). Once again, in passing from the basic electrostatic model to more advanced formulations other contributions are collected in this term. The constant energy terms corresponding to f/1 and to nuclear repulsion are not reported in Equation (1.107). [Pg.84]

But these mathematical tools have to be used in the service of fundamental physical ideas. This opinion had already been expressed by Dirac to maintain physics on the foreground and examinate, as often as possible, the physical sense hidden under the mathematical formalism. [22] In the 1950s, the wave equation was insoluble, except for the molecules of hydrogenic character. As a matter of fact, the chemist introduces just those functions which correspond to the behavior to be expected chemically. [23] Mathematical operations have to be guided In practically the whole of theoretical chemistry, the form in which the mathematics is cast is suggested, almost inevitably, by experimental results. [24]... [Pg.109]

It may be that the wave functions are eigenfunctions of two non-commuting operators corresponding to physical quantities such as p (momentum) and q (position) respectively. Then, by measuring either A or B in system I, it becomes possible to predict with certainty and without disturbing the second system, either the value of Pk or qr. In the first case p is an element of reality and in the second case q is an element of reality. But ipk and commuting operators cannot have simultaneous reality. It was inferred that quantum theory is incomplete. [Pg.71]


See other pages where Function operator corresponding is mentioned: [Pg.67]    [Pg.189]    [Pg.112]    [Pg.67]    [Pg.189]    [Pg.112]    [Pg.485]    [Pg.287]    [Pg.749]    [Pg.307]    [Pg.81]    [Pg.48]    [Pg.266]    [Pg.274]    [Pg.1538]    [Pg.213]    [Pg.68]    [Pg.96]    [Pg.119]    [Pg.183]    [Pg.316]    [Pg.504]    [Pg.505]    [Pg.67]    [Pg.137]    [Pg.101]    [Pg.380]    [Pg.26]    [Pg.439]    [Pg.3]    [Pg.509]   
See also in sourсe #XX -- [ Pg.469 ]




SEARCH



Function operator

Operators functional

© 2024 chempedia.info