WorldCat Identities

Vizbaraite, Ya I.

Overview
Works: 18 works in 18 publications in 1 language and 19 library holdings
Publication Timeline
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Most widely held works by Ya I Vizbaraite
Tables for the calculation of matrix elements of operators of atomic quantities by R. I Karaziya( Book )

1 edition published in 1967 in English and held by 2 WorldCat member libraries worldwide

Theoretical study of transitions with different types of coupling using the nitrogen atom as an example( Book )

1 edition published in 1967 in English and held by 1 WorldCat member library worldwide

A theoretical study is made of transitions of the type '2p(2) (3P) 3d(2S+1)Lf to 2p(2) (3P) 4fL (K) F' with the application of both LS0-coupling and J0L-coupling for the configuration 2p(2)4f
Selection rules of two-electron transitions (k voprosu o pravilakh otbora dvukhelektronnykh perekhodov)( Book )

1 edition published in 1966 in English and held by 1 WorldCat member library worldwide

It is shown that prohibition of the simultaneous transition of two electrons does not follow from the approximation provided by the conventional application of the Fock self-consistent field. The multiconfiguration approximation is used to derive the selection rules for two-electron transitions in the case of electric dipole radiation. These rules agree with corresponding selection rules obtained by the method of partial separation of variables. (Author)
The mathematical problem of the multiconfiguration approximation (matematicheskaya zadacha mnogokonfiguratsionnogo priblizheniya)( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

The Ritz method is generalized in the sense that it is combined with the variation method to find approximate eigenfunctions. It is shown that this generalized Ritz method comprises a mathematical basis for the method of the Fock self-consistent field in the multiconfiguration approximation. Methods are indicated for simplifying the corresponding equations, which permit calculations to be carried out without certain difficulties connected with the nonsimplified equations. (Author)
Properties of orbitals in the extended method of calculation (o svoistvakh volnovykh funktsii v rasshirennom metode rascheta)( Book )

1 edition published in 1966 in English and held by 1 WorldCat member library worldwide

The constants of orbitals of the same shell differ greatly from each other, which leads to an extension of the theory as compared to the conventional method of calculation. Apparently, the energy does not reach its minimum with only a single set of constants of the orbitals, which indicates the practical equality of the two constants with q = 4, but not with any other value of q. In all cases, the energy data are improved in the transition from the conventional method to the extended method. (Author)
The multiconfiguration approximation for atomic species of helium type (mnogokonfiguratsionnoe priblizhenie v sluchae atomov tipa geliya)( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

The multiconfiguration approximation is applied to the ground configuration of atomic species of helium type from H( - ) to C(4+) by a method in which the results of the self-consistent field are used for the ground configuration, while the corrections to the energy for the multiconfiguration approximation are determined with hydrogen-like analytic wave functions. The resulting values of the total energy are compared with the results of application of the method of partial separation of variables and with the experimental data. (Author)
Theoretical determination of the isotope shift in the spectra of helium and the positive lithium ion (o teoreticheskom opredelenii izotopicheskogo smeshcheniya v spektre geliya i polozhitelnogo iona litiya)( Book )

1 edition published in 1966 in English and held by 1 WorldCat member library worldwide

The multiconfiguration approximation is used to determine the specific effect of mass on the energy of the ground configuration of the helium atom and the positive lithium ion, while the effect is determined in a single-configuration approximation for the configurations lsnp(n=2 ...,6) on the basis of orbitals of the Fock self-consistent field. The energy values of the isotope shift contributed by the mass effect are given for the isotopes of the helium atom of masses 4 and 3 and compare them with experimental data. The shift of a number of spectral lines for the isotopes of the helium atom of masses 4 and 3 and the isotopes of the positive lithium ion of masses 7 and 6 is determined with a rejection of the approximation of the one-electron-state model. The results obtained are compared with the results determined in an approximation of the one-electron-state model based on analytic orbitals, and with experimental data in cases where such data are available. (Author)
On the calculation of line strengths and selection rules with various types of couplings( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

The expressions for matrix elements of electric multipole operator coupling levels with various types of vector coupling are given. The cases of different types of coupling in the initial and final levels are also considered. Selection rules for the mentioned cases are established. They are expressed by polygonal rules presenting nonvanishing conditions of j-coefficients appearing in expressions of matrix elements of electric multipole operator. Maximum number of sides in these polygons is equal to five. (Author)
Determination of spectral line strength by the expansion calculation method( Book )

1 edition published in 1963 in English and held by 1 WorldCat member library worldwide

Operators of electric-dipole and quadrupole transitions are defined in irreducible tensor form. In the case of the quadrupole, they differ from the corresponding operator employed in other contexts, because they have a constant factor. Expressions are found which permit a change from the ordinary method of calculation to an extended method in determining the line strength for configurations of two equivalent electrons. Numerical values are given for the line strength in the 1s(2) - 1s2p, 2p(2) - 1s2p and 1s(2)2p(2) 1s(2)2s2p dipole transitions for a number of atoms and ions, and in the 2p(2) - 2p(2) quadrupole transition for the carbon atom. (Author)
Formulating a generalized hartree method (k voprosu o postroenii obobshchennogo metoda khartri)( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

In this paper it is shown that the orbitals of individual configurations of a multiconfiguration approximation are slightly dependent on the terms of a given configuration as well as on the type of coupling. The generalized method of the Fock self-consistent field, which consists of its extension to a multiconfiguration approximation, is contrasted with the generalized Hartree method, in which the linear combination of products of radial orbitals is used as the variation wave function to find the orbitals, while all the other calculations are carried out in accordance with the generalized Fock method. The suggested method for the helium atom yielded practically the same results as the complete generalized Fock method. (Author)
Fock self-consistent field in the two-configuration approximation for atomic species of boron type (samosoglasovannoe pole foka v dvukhkonfiguratsionnom priblizhenii dlya atomov tipa bora)( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

Solutions to the Fock equation in the two-configuration approximation are presented for the 2p radial orbital of the excited configuration of the two-configuration approximation 1s(2)2s(2)2p-1s(2)2p(3) and the energy values of the 2s and 2p electrons for B, C(+), N(++), and O(3+). (Author)
Application of the multiconfiguration approximation to atomic species of carbon, nitrogen, and oxygen type (k voprosu o primenenii mnogokonfiguratsionnogo priblizheniya v sluchae atomov tipa ugleroda, azota i kisloroda)( Book )

1 edition published in 1966 in English and held by 1 WorldCat member library worldwide

The problem examined is the form of the multiconfiguration approximation that should be employed to improve the calculation of atomic species of carbon, nitrogen, and oxygen type. It is shown how to express the elements of the energy matrix with radial integrals when applying the multiconfiguration approximation to a configuration of equivalent electrons on the basis of the model of two-electron states. A way is found to determine the correction to the energy for the multiconfiguration approximation in configurations containing any number of equivalent electrons. This is done with corrections for configurations with two equivalent electrons. Numerical values are given for the ratios of term separations for several atomic species of carbon, nitrogen, and oxygen type as determined by multiconfiguration approximations based on the model of two-electron states. An appendix contains the formulas of quantities from the theory of vector addition of angular momenta that are needed in deriving formulas for certain elements of the energy matrix. (Author)
The fock self-consistent field in the multiconfiguration approximation for the helium atom (samosoglasovannoe pole foka v mnogokonfiguratsionnom priblizhenii diya atoma geliya)( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

The solution of the Fock equations are presented in two-configuration approximation for the configurations 2p(2), 2s(2), 3d(2), and 3p(2), regarded as excited configurations with respect to the ground configuration of the helium atom. These solutions are used to evaluate the correction to the energy of the ground configuration for various multiconfiguration approximations. The value of the energy as determined by the Fock self-consistent-field method is presented in the six-configuration approximation 1s(2)-2p(2)-2s(2)-3d(2)-3p(2)-2p3p and compared with the experimental energy value. (Author)
Fock self-consistent field in the two-configuration approximation for nitrogen in various degrees of ionization (samosoglasovannoe pole foka v dvukhkonfiguratsionnom priblizhenii dlya atoma azota v raznykh stepenyakh ionizatsii)( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

The Fock equation in the two-configuration approximation is solved for the 2p radial orbital of the excited configuration 1s(2)2p(q+2) of the two-configuration approximation 1s(2)2s(2)2p(q)-1s(2)2p(q+2) with q = 2, 3, and 4 in the case of nitrogen. Energy values of the 2s and 2p electrons are determined and compared with the experimental data. (Author)
Theoretical determination of the magnetic susceptibility of light atoms( Book )

1 edition published in 1966 in English and held by 1 WorldCat member library worldwide

A refined method of calculation that includes both the multiconfiguration approximation and the method of partial separation of variables in the approximation of the two-electron-state model is applied to the theoretical determination of magnetic susceptibility. The authors present and discuss a number of numerical results for atoms (ions) of helium type, beginning with H( - ) and ending with C(4+), and of beryllium type, beginning with Li( - ) and ending with C(2+)
Refinement of the calculation of forbidden spectral lines (ob utochenenii rascheta azpreshchennykh spektralnykh linii)( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

Forbidden spectral lines include electric quadrupole and magnetic dipole transitions. In view of the practical impossibility of laboratory study of such lines, their theoretical calculation acquires special significance. It turns out that a rather significant refinement of the calculation is realized by the selection of a suitable type of coupling in the initial and final states of the atom or ion. If the examination involves equivalent electrons, the coupling in the general case is intermediate between two types of homogeneous coupling. In the case of nonequivalent electrons, nonhomogeneous couplings acquire great significance. The first of these couplings are formally simple, but the second correspond to consecutive addition of momenta. The results of allowance for nonhomogeneous couplings in the study of forbidden lines are illustrated with the two-electron spectrum as an example. (Author)
The forms of the equations of the self-consistent field (o vidakh uravnenii samosoglasovannogo polya)( Book )

1 edition published in 1965 in English and held by 1 WorldCat member library worldwide

It is pointed out that neglect of the exchange terms between shells in the Fock equations leads to equations that differ substantially from the Hartree equations in the general case. However, the use of an atomic wave function in the form of a single product of orbitals is ambiguous. It is shown that the Hartree equations can be obtained unambiguously by the use of an atomic function in the form of a product of radial orbitals. The atomic wave function expressed as a single determinant in the 'unrestricted' Hartree-Fock method is pointed out to be ambiguous. (Author)
Theoretical determination of the probability of an electric quadrupole transition (k voprosu o teoreticheskom opredelenii veroyatnosti elektricheskogo kvadrupolnogo perekhoda)( Book )

1 edition published in 1966 in English and held by 1 WorldCat member library worldwide

The process of calculations on the theoretical determination of the electric quadrupole strength is systematized to a certain extent. The requisite formulas of the mathematics of tensor operators are given for configurations with one and two unfilled shells. It is shown how to apply the multiconfiguration approximation to the theoretical determination of the probability of a quadrupole transition. The effect of the multiconfiguration approximation on the results of calculations for atomic species of carbon, nitrogen, and oxygen type is examined. The radial integral appearing in the expression for the probability of a quadrupole transition is evaluated both with analytic orbitals and with solutions to the Fock self-consistent-field equations for a number of atomic species of the aforementioned types. (Author)
 
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English (18)