ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Spatial correlation of electrons in metals (1988)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 34 (1988), S. 655-664 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of electron-electron repulsions is assessed, primarily in the expanded fluid alkali metals, by confronting experimental data on these systems with the predictions of theory. This is usefully divided into two types of approach: (i)full inclusion of the long-range Coulomb interaction e2/rij between electrons i and j, but perturbative treatment of electron-ion interaction and(ii)the simplified on-site interaction described by the Hubbard U.The main conclusion is that both electron-ion and electron-electron correlations are of major importance in the expanded fluid alkali metals, and especially in Cs. The momentum distribution of the conduction electrons is changed in a very important quantitative way from the predictions of the jellium model at the same density by the electron-ion interaction. This leads to a metal-insulator transition at a much higher electron density than the jellium prediction. The relevance of this conclusion to crystalline alkalis is finally referred to.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560340867
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Asymptotic forms of atomic scattering factors and momentum densities (1980)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 17 (1980), S. 833-844 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Within the framework of the nonrelativistic Schrödinger equation, the Coulomb field case is used to assess the range of validity of the Thomas-Fermi statistical theory of atoms. In particular, attention is focused on (a) the x-ray scattering factor, which is the Fourier transform of the electron density; and (b) the momentum density. In each case the predictions of the statistical theory are compared with the exact results for the Coulomb potential. These can conveniently be calculated using earlier work of Fock. Some assessment is also made of the accuracy of the statistical approximation for the kinetic energy density; this is of interest in connection with the density functional approach. Finally, some brief comments are made on the relation between the self-consistent Thomas-Fermi method and the Hartree theory for atoms.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560170503
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Generalized 1/Z expansion for heteronuclear molecules (1986)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 29 (1986), S. 949-958 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have first studied empirical regularities in various series of heteronuclear diatomic molecules between the energy E, the total number of electrons N, the equilibrium distance Re and Z̄ = (Z1Z2)1/2 where Z1e and Z2e are the nuclear charges in the diatom. In particular, for various alkali halide series, Re2|E|/N5/3 is shown to correlate rather simply with Z̄Re3. Some theoretical basis is afforded by generalizing the 1/Z expansion used early by the writers in work on homonuclear diatomics. Finally, when Z2/Z1 → ∞, a model is presented which predicts a finite asymptotic bond length and this prediction is confronted with available experimental data for both heteronuclear diatoms and for the polyatomic series CH4 to SnH4.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560290431
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Dimensionality dependence of total energy of closed shells in a bare Coulomb field for large atomic number (1988)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 33 (1988), S. 301-304 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For Z particles moving independently in an unscreened Coulomb potential energy -Ze2/r, it is known that the total energy E = -(3/2)1/3Z7/3 in nonrelativistic theory as Z→∞. The generalization of this result to d dimensions in the same asymptotice limit is obtained as \documentclass{article}\pagestyle{empty}\begin{document}$$E(Z,d) = - \frac{{2\left({\frac{{d!}}{4}} \right)^{1 - (2/d)} }}{{(d - 1)!(d - 2)}}Z^{3 - (2/d)},$$\end{document} which includes the known result above for the three-dimensional case.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560330405
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Relativistic theory of binding energies of heavy positive ions (1981)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 20 (1981), S. 693-704 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The self-consistent relativistic Thomas-Fermi theory of heavy positive ions with N electrons and nuclear charge Ze is shown to lead to a chemical potential μ which has the scaling property \documentclass{article}\pagestyle{empty}\begin{document}$$ \mu = Z^{4/3} F\left( {N/Z;\;\varepsilon /Z^{2/3} } \right), $$\end{document} with ∊ = α2Z2, α being the fine structure constant. Combining this with the Layzer-Bahcall expansion for the total energy E(Z, N), namely, \documentclass{article}\pagestyle{empty}\begin{document}$$ E(Z,N) = Z^2 \sum\limits_{n = 0}^\infty {\sum\limits_{m = 0}^\infty {E_{mn} (N)\varepsilon ^m Z^{ - n} } } $$\end{document} it is proved that the coefficients Enm (N) at large N have the asymptotic behavior Nn-2m/3#1/3. The corresponding result for the scaling of the relativistic Thomas-Fermi energy is \documentclass{article}\pagestyle{empty}\begin{document}$$ E_{{\rm TF}} (Z,N) = Z^{7/3} F_1 (N/Z;\varepsilon /N^{2/3} ). $$\end{document} Scaling properties of the higher order terms in Enm (N) and E(Z, N) are also proposed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560200311
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Relativistic total energy of heavy atomic ions: Dimensionality dependent scaling (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 27 (1985), S. 595-599 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The scaling property of the relativistic total energy E (Z, N) established by Marconi and the writer for heavy positive ions with N electrons and atomic number Z is demonstrated, by setting up the self-consistent relativistic Thomas-Fermi equation in d dimensions, to be a special case of the scaling property \documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {E_d (Z,N,\alpha ) = Z^{{{(4 + 4d - d^2 )} \mathord{\left/ {\vphantom {{(4 + 4d - d^2 )} {d(4 - d)}}} \right. \kern-\nulldelimiterspace} {d(4 - d)}}} F_d ({N \mathord{\left/ {\vphantom {N {Z;\alpha ^2 Z^{{4 \mathord{\left/ {\vphantom {4 {d(4 - d)}}} \right. \kern-\nulldelimiterspace} {d(4 - d)}}} }}} \right. \kern-\nulldelimiterspace} {Z;\alpha ^2 Z^{{4 \mathord{\left/ {\vphantom {4 {d(4 - d)}}} \right. \kern-\nulldelimiterspace} {d(4 - d)}}} }});} {d \ne 4,} \\ \end{array} $$\end{document} α being the fine structure constant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560270508
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Electron momenta in molecules and low-dimensional solids (1986)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 30 (1986), S. 367-376 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Relations between wave-mechanically calculated moments of momentum 〈pn〉, with n = 2, 1, and - 1, for some light diatoms are first compared with electron density approximations given by In = ∫{ρ(r)}1 + n/3. Whereas the ratios 〈pn〉/In are predicted by semiclassical theory as 5.74, 2.32, and 0.48, respectively, the calculated values with densities of Hartree-Fock-Roothaan quality are 6.36, 2.38, and 0.42, respectively. Polyatomics, including the almost spherical XHn molecules, are then considered, with some attention focusing on methane, followed by a comparison between some empirical results for the Compton profile of hydrocarbons and the bond profile C—H related to the methane Compton line shape. Some understanding of the empirical results of Eisenberger and Marra is thereby gained. After a brief discussion of momenta in graphite, we consider the electron-electron pair function of polyacetylene in momentum space in relation to that in a three-dimensional electron liquid, such pair correlation being related to plasmon dispersion.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560300734
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Approximate density-external potential relation and the pauli potential for systems with coulombic interaction (1989)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 36 (1989), S. 741-748 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Earlier work on the Pauli potential VPauli, which allows the square root of the electron density to be calculated directly from a Schrödinger equation, is generalized from two-level (radial) systems such as the Be atom to the n-level case in one dimension. This is achieved using hyperspherical functions, in terms of which the first- and second-order density matrices are expressed. It is confirmed that VPauli can be constructed from the ground-state density ρ (x) and its first two derivatives, plus the functional derivative of the single-particle kinetic energy with respect to ρ. Finally, contact is made with the Harriman construction, but now using approximate one-body orbitals.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560360606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Electron-Electron interaction energy in homonuclear diatomic molecules (1989)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 36 (1989), S. 525-531 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The derivative of the electron-electron potential energy Uee with respect to internuclear separation R is studied for light homonuclear diatomic molecules at equilibrium. It is readily related to nuclear-nuclear potential energy Unn, the force constant K, and the electron-nuclear potential energy Uen. An approximate expression, based on the simplest form of density functional theory, is then used to eliminate dUen/dR|Re. The result thus obtained for dUee/dR|Re transcends an earlier proposal of Kryachko by including a term 2/3ReK, with K the force constant. Numerical tests at SCF-RHF level are presented for nine homonuclear diatomic molecules.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560360407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Explicit density-potential relation for 4-electron atoms in 2-orbital S states (1989)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 35 (1989), S. 649-663 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An explicit relation is derived between the one-body potential energy and the electron density for the ground state of the Be atom in a nonrelativistic framework. This same relation applies to any four-electron atomic ion (or to Be itself) in a state where the electrons occupy two doubly filled orbitals. The relation is interpreted as an exact Hartree-like model of the Hohenberg-Kohn theorem within the general context of N electrons and a potential that is not necessarily spherically symmetrical.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560350506
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...