Big Chemical Encyclopedia

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

Articles Figures Tables About

Transformation matrix Determinant

We intend to show that an adiabatic-to-diabatic transformation matrix based on the non-adiabatic coupling matrix can be used not only for reaching the diabatic fi amework but also as a mean to determine the minimum size of a sub-Hilbert space, namely, the minimal M value that still guarantees a valid diabatization. [Pg.678]

The transformation matrix is determined by the requirement that the sum of square overlaps be maximized. The Ri are simple reference wavefunc-... [Pg.350]

A sinusoidal plot of grf>2 vs.

crystal plane gives another set of Ks that depend on other combinations of the gy, eventually enough data are obtained to determine the six independent values of gy (g is a symmetric matrix so that gy = gy,). The g-matrix is then diagonalized to obtain the principal values and the transformation matrix, elements of which are the direction cosines of the g-matrix principal axes relative to the crystal axes. An analogous treatment of the effective hyperfine coupling constants leads to the principal values of the A2-matrix and the orientation of its principal axes in the crystal coordinate system. [Pg.54]

Single-valued potential, adiabatic-to-diabatic transformation matrix, non-adiabatic coupling, 49-50 topological matrix, 50-53 Skew symmetric matrix, electronic states adiabatic representation, 290-291 adiabatic-to-diabatic transformation, two-state system, 302-309 Slater determinants ... [Pg.98]

The process of determining the transformation matrix provides a chance to check that the current basis is thermodynamically valid. In the previous chapter we noted that if a basis is valid, it is impossible to write a balanced reaction to form one entry in terms of the other entries in the basis. [Pg.74]

The transformation matrix is orthogonal of order 2. With every element T() of the group can be associated a 2 x 2 orthogonal matrix with determinant +1 and the correspondence is one-to-one. The set of all orthogonal matrices of order 2 having determinant +1 is a group isomorphic to 0(2) and therefore provides a two-dimensional representation for it. The matrix group is also denoted by the symbol 0(2). [Pg.89]

Another method to determine the magnitude and rhombicity of the alignment tensor is based on the determination of the Saupe order matrix. The anisotropic parameter of motional averaging is represented by this order matrix, which is diagonalized by a transformation matrix that relates the principal frame, in which the order matrix is diagonal,... [Pg.190]

A is a linear transformation matrix which allows one to transform from one "best-fit solution to another (from the unprimed set to the primed set mentioned above). In order to specify a particular solution (and a unique transformation matrix A to get to that solution from some arbitrary solution), four E and C parameters may ) be chosen and assigned specific values, as long as they are chosen in such a way that the transformation from our arbitrary solution is completely defined and finite, i.e., the four parameters must be chosen so that the elements of A, fly, are completely defined and the determinant of A must be nonzero in order that A- exist, [flu fl22 — i2 ai 9 0]. These require-... [Pg.101]

Although they did not obtain a closed-form analytic expression for the three-dimensional case, they dealt with a trasformed one-matrix for the single Slater determinant constructed from plane waves, and rewrote the energy in terms of this transformed matrix. The conditions on the transformation were not imposed through the Jacobian but rather through the equations ... [Pg.174]

In 1983, Sasaki et al. obtained rough first approximations of the mid-infrared spectra of o-xylene, p-xylene and m-xylene from multi-component mixtures using entropy minimization [83-85] However, in order to do so, an a priori estimate of the number S of observable species present was again needed. The basic idea behind the approach was (i) the determination of the basis functions/eigenvectors V,xv associated with the data (three solutions were prepared) and (ii) the transformation of basis vectors into pure component spectral estimates by determining the elements of a transformation matrix TsXs- The simplex optimization method was used to optimize the nine elements of Tixi to achieve entropy minimization, and the normalized second derivative of the spectra was used as a measure of the probability distribution. [Pg.177]

Note that = det is the determinant of the 3N x 3N transformation matrix 8R /8g , which gives the Jacobian for the transformation from generalized to Cartesian coordinates. This follows from the fact that the right-hand side (RHS) of Eq. (2.16) for g p is a matrix product of this transformation matrix with its transpose, and that the determinant of a matrix product is a product of determinants. By similar reasoning, we find that... [Pg.72]

What conclusions do these examples suggest First, note that only the hrst six examples are orthogonal transformations. The determinant of each of these matrices is +1 or —1. Every matrix that represents an orthogonal transformation must have determinant 1. However, one example shows that the determinant of a nonorthogonal transformation can be 1. (Which example )... [Pg.35]

Exercise 4.18 Show that a 2 x 2 matrix M is a unitary transformation of determinant one on if and only if there are complex numbers a and f such that ce P + f = 1 and... [Pg.147]

Referring to Fig. A.2, assume that the principal coordinates align with z, r, and O. The unit vectors (direction cosines) just determined correspond with the row of the transformation matrix N. Thus, if the principal stress tensor is... [Pg.760]

Using matrix multiplication, carry out the required similarity transformations to determine the arrangement of the twelve operations in the group T into classes. [Pg.99]

The transformation matrix X is determined experimentally and is related to the rate constant matrix, K ... [Pg.539]

Under a crv plane Y/,o is unchanged, while Y/)+m and Y,-m transform into a linear combination this is easily determined from one of the transformation matrix expressions given above. [Pg.170]

In order to eliminate the problems with the invariance, we proposed some time ago a topological approximation based on the so-called overlap determinant method [43]. This approximation is based on the transformation matrix T that describes the mutual phase relations of atomic orbitals centred on molecules R and P, and thus plays in this approach the same role as the so-called assigning tables in the overlap determinant method (Eq. 4)... [Pg.3]

Of the 15 experimentally known phases of the higher oxides only five of them have been determined by X-ray and neutron diffraction using the Rietveld refinements method. To understand the thermodynamic behavior and phase reactions it is helpful to have a model of the undetermined structures. Using the experimental electron diffraction data it is possible to determine the symmetry of the unit cell and develops a transformation matrix between the fluorite and ten of the intermediate phases as shown in Table 2. The module theory provides a method for modeling the unknown structures of the homologous series of the lanthanide... [Pg.36]

In fact the relative coefficients within a set of symmetrically equivalent atoms, such as Cl, C3, C5, and Cg in para-benzosemiquinone, can be determined by group theory alone. The appropriate set of symmetrized orbitals, also listed in Table 1, can be obtained by use of character tables and procedures described in Refs. 3 to 6. In matrix notation, the symmetrized combinations are <1> = Up, where <1) and p are column vectors and U is the transformation matrix giving the relations shown in part (c) of Table 1. The transformation U and its transpose U can be used to simplify the solution of the secular matrix X since the matrix multiplication UXU gives the block diagonal form shown in part (6) of Table 1. [Pg.463]

TABLE 1.3. Types of Lattice Symmetry Based on the Values of the Translation Vector T, the Transformation Matrix W, and its Determinant... [Pg.14]

Equation 10.1 is a second-rank tensor with transpose symmetry. The normal components of stress are the diagonal elements and the shear components of stress are the nondiagonal elements. Although Eq. 10.1 has the appearance of a [3 x 3] matrix, it is a physical quantity that, for one set of axes, is specified by nine components, whereas a transformation matrix is an array of coefficients relating two sets of axes. The tensor coefficients determine how the three components of the force vector, /, transmitted across a small surface element, vary as different values are given to the components of a unit vector / perpendicular to the face (representing the face orientation) ... [Pg.405]

Autunite is well-known to dehydrate rapidly to form meta-autunite, for whieh no satisfactory structure model has yet been presented. A method of direet synthesis of meta-autunite has not been reported, and its formation by dehydration of autunite likely induces so much mosaic spread that single crystal structure determinations have not been successful. Autunite may be eonsidered to exhibit pseudosymmetry, as the transformation matrix [- /2OO/OOI/OIO] yields a metrically tetragonal cell. [Pg.251]


See other pages where Transformation matrix Determinant is mentioned: [Pg.5858]    [Pg.5858]    [Pg.150]    [Pg.72]    [Pg.73]    [Pg.170]    [Pg.226]    [Pg.62]    [Pg.72]    [Pg.170]    [Pg.19]    [Pg.141]    [Pg.70]    [Pg.71]    [Pg.311]    [Pg.411]    [Pg.23]    [Pg.463]    [Pg.157]    [Pg.77]    [Pg.157]    [Pg.106]   
See also in sourсe #XX -- [ Pg.14 ]




SEARCH



Determining the transformation matrix

Matrix determinant

Matrix transform

Matrix transformation

© 2024 chempedia.info