Big Chemical Encyclopedia

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

Articles Figures Tables About

Operator translational

The column vector is indicated by square brackets, a row vector by round brackets. The quantum numbers may be determined by the complete set of her-mitian operators commuting with the generator of time evolution. Invariance of the quantum state to frame rotation, origin displacement, parity and other symmetry operations determine quantum numbers for the corresponding irreducible representations. Frame related symmetry operations translate into unitary operator acting on Hilbert space (rigged), e.g. Ta. [Pg.179]

This operator translates the eigenkets of the position operator according to... [Pg.410]

It was easy to show that we can formulate the method also in the case of a combined symmetry operation (for instance helix operation = translation + rotation) instead of simple translation ( ). In this case k is defined on the combined symmetry operation and from going from one cell to the next one, one has (1) to put the nuclei in the positions required by the symmetry operation and (2) one has to rotate accordingly also the basis set. [Pg.74]

We introduce here the concept of logistic drivers making the link between the company s strategic objectives and their operational translation in the supply chain. These drivers are in line with the aim of logistics as defined by James Hesket (1977) in these terms Respond to demand at a given level of service at the lowest cost and also cross-check with Martin Christopher s dictum. Four in total, they incorporate in addition the new environmental component. We quote ... [Pg.42]

Gambutrtsev, S., I. Iliev, and A. Kaisheva (1983). Influence of the pyrolysis products of cobalt tetramethoxyphenylporphyrin in activated charcoal on the behavior of hydrophobic carbon air electrodes during prolonged operation. Translated from Aektrokhimiya 19, 1261-1264. [Pg.148]

M Inertial mass or global mass transfer operator [translational mechanics or physical chemistry]... [Pg.750]

Operations that are in Use in Physick, Illustrated with Many Curious Remarks and Useful Discourses upon each Operation. Translated by Walter Harris. London W. Kettilby. [Pg.318]

Remark 3.2. Lemma 3.1 is an easy consequence of linear algebra over the finite field Z2. Indeed, the elements of the set S can be identified with the coordinates of which is an 5 -dimensional vector field over Z2. Under this identification, the subsets of S are vectors in that vector space, and the condition that the family E is closed under the operation translates to the fact that U is a linear subspace of Z2. Say this subspace has dimension d. Then by linear algebra over Z2, we see that L = 2. ... [Pg.38]

First we fix notation. For an arbitrary cell complex X, we let X denote the set of d-dimensional cells of X (this is different from taking a d-skeleton). Since we are working with coefficients from Z2, we may identify d-cochains with their support subsets of X . Under this identification, the cochain addition is replaced by the symmetric difference of sets, which we denote by the symbol . The coboundary operator translates to... [Pg.335]

An amorphous solid is characterized by the lack of long-range order symmetry operators (translational, orientational, and conformational order) found in crystalline solid. The absence of long-range order can be ascribed to a random distribution of molecular units. Individual molecules are randomly oriented to one another and exist in a variety of conformational states. The molecular pattern of an amorphous solid is often depicted as that of a frozen liquid with the viscosity of a solid having many internal degrees of freedoms and conformational diversities (disorder). An amorphous solid, at the molecular level, has properties similar to liquids but at the macroscopic level, it has properties of solids. [Pg.5]

Fig. 12.3 A relay-operated translating machine, for binary to decimal. Fig. 12.3 A relay-operated translating machine, for binary to decimal.
Space Group. The 3-dimensional symmetry of a crystal structure (q.v.) which is developed by applying symmetry operations (translation, rotation, reflection) to the 14 bravais... [Pg.302]

Space groups are groups that combine certain point group operations, translational symmetry elements, and their products. [Pg.551]

We will need a systematic way to deduce whether a molecular property is symmetric or antisymmetric with respect to the symmetry operations for that molecule s point group, as things will quickly get more complicated. To this end, we define a number, Xp( )> called a character, which expresses the behavior of our property p when operated on by the symmetry operation, R. A collection of characters, one for each symmetry operation present in a point group, forms a representation, Fp. The property is technically referred to as the basis vector of the representation, Fp. We can define aU sorts of basis vectors, some of which have very little apparent connection to our original molecule, such as the non-symmetry operation translate along the z axis , often given the symbol z, or the non-symmetry operation rotate by an arbitrary amount about the X axis, often referred to as R. Strictly speaking, the characters are the trace of the transformation matrix for each symmetry operation, applied to the property, p. This is described in more detail in the on-line supplementary section for Chapter 2 on derivation of characters. [Pg.17]

The formalism of the a initio Hartree-Fock CO method first proposed about 15 years ago (2,3) has been discussed in details elswhere (1,4) (see also the contribution of J. Ladik in this Volume), It has to be noted that in the case of a helix one steps from unit to unit, not with a simple translation but with a combined symmetry operation (translation along the helix axis and rotation around it). Therefore, one has to rotate both the atoms in the elementary cell and also the atomic orbitals centered on these atoms. This means that, having chosen the z axis along the main axis of the helix, the atomic orbitals with components in the xy plane have to be rotated (18). Second neighbors interactions have been included with a correct electrostatically balanced cutoff (19) of the different types of integrals. [Pg.364]


See other pages where Operator translational is mentioned: [Pg.407]    [Pg.168]    [Pg.229]    [Pg.67]    [Pg.4]    [Pg.345]    [Pg.161]    [Pg.537]    [Pg.288]    [Pg.337]    [Pg.714]    [Pg.281]    [Pg.180]    [Pg.249]    [Pg.28]    [Pg.347]   
See also in sourсe #XX -- [ Pg.25 , Pg.29 ]




SEARCH



Lattice translation operation

Multipole translation operator

Rotation and translation operators do not commute

The kinetic energy operators of translation, rotation and vibrations

Translation operator

Translation operator

Translation operators, vibrational modes

Translational symmetry operators

© 2024 chempedia.info