Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Inorganic Chemistry  (14)
  • 82.65  (3)
  • 14.80.Pb  (2)
  • Rare earth elements  (2)
Material
Keywords
  • 1
    ISSN: 1434-601X
    Keywords: 14.80.Pb ; 13.10. + q ; 12.20.Fv
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Motivated by the observation of energy- and momentum-correlatede + e − pairs in heavy ion collisions, a search for resonances ine + e − scattering at the corresponding energies has been made. Thee + e − decay channel is analyzed in a time window from ∼ 10−13 s to ∼ 10−11 s with a set-up optimized for low-background detection of delayede + e − decays. The two-photon decay channel of a hypothetical resonance is investigated by measuring the two-photon annihilation-in-flight excitation function. New upper limits for the partiale + e − decay width Γee of a few meV are derived for total centre-of-mass energies √s between 1.78 and 1.92 MeV, taking into account the dilepton as well as the two-photon decay of a neutral resonance.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 75 (1989), S. 369-387 
    ISSN: 1432-2234
    Keywords: Pseudopotentials ; Rare earth elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nonrelativistic and quasirelativistic energy-adjusted pseudopotentials for fixed 4f subconfigurations of the rare earth elements La through Lu together with corresponding optimized valence basis sets have been used in SCF and CI(SD) calculations to determine the spectroscopic constants for the energetically low lying superconfigurations of the lanthanide monohydrides, monoxides and monofluorides. The experimentally observed trends in dissociation energies, bond lengths and vibrational frequencies for the ground states of the calculated superconfigurations of the monoxides and monofluorides are well reproduced. The results for the monohydrides are mainly predictions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 75 (1989), S. 173-194 
    ISSN: 1432-2234
    Keywords: Pseudopotentials ; Rare earth elements
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nonrelativistic and quasirelativistic energy-adjusted pseudopotentials and optimized (7s6p5d)/[5s4p3d]-GTO valence basis sets for use in molecular calculations for fixed f-subconfigurations of the rare earth elements, La through Lu, have been generated. Atomic excitation and ionization energies from numerical HF, as well as SCF pseudopotential calculations using the derived basis sets, differ by less than 0.1 eV from numerical HF all-electron results. Corresponding values obtained from CI(SD), CEPA-1, as well as density functional calculations using the quasirelativistic pseudopotentials, are in reasonable agreement with experimental data.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1434-601X
    Keywords: 13.10.+q ; 12.20.Fv ; 14.80.Pb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A monoenergetic positron (e +) beam (ΔT/T〈5·10−4) from the Stuttgart pelletron accelerator and a 4.6 mg/cm2 Be target has been employed to investigatee + e −scattering in the MeV region in a large solid angle with high statistics by means of a novel positionsensitive detector system. Superimposed on the Bhabha scattering, a structure has been found at ane + kinetic energy of 2263 keV (810 keV excitation energy in thee + e −rest frame). From the energy-integrated resonance cross-section of $$\sigma _{res} \cdot \Gamma _{res}^{e^ + e^ - } $$ ≅30 b·eV (c.m.) and the standard resonance cross-section we estimate partial resonance widths $$\Gamma _{res}^{e^ + e^ - } $$ ≅72 meV or 24 meV for total angular momenta J=0 or J=1, respectively. The structure, which has not been predicted within the framework of quantum electrodynamics, coincides with one of the sum energies of the correlatede + e −lines observed in heavy-ion collisions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 15 (1990), S. 79-86 
    ISSN: 1434-6079
    Keywords: 31.20 ; 36.40 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The alternating process of adsorption of Ag+ and trapping of a photoelectron on a (100) AgBr surface is investigated by quantum chemical calculations. The results give some insight into the initial steps of the photographic process (absorption of two photons which lead to the formation of a sublatent image).
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 6 (1987), S. 193-198 
    ISSN: 1434-6079
    Keywords: 31.15 ; 36.40 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Having studied free silver clusters by quantum chemical calculations we now present a method to take into account the influence of a silver halide surface on adsorbed silver clusters. The model for the surface will be a silver halide cluster as frozen crystal section. The interactions are discussed in detail; a new bromide pseudopotential may be of special interest. Results with this method will be given in subsequent papers.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 6 (1987), S. 287-292 
    ISSN: 1434-6079
    Keywords: 31.20 ; 36.40 ; 82.65
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The adsorption of Ag+ and Ag on a (100) AgBr surface is investigated. Interstitial subsurface sites and incomplete surfaces (with ledges and kinks) are also considered. Equilibrium geometries, adsorption energies and ionization potentials have been calculated. Migration of neutral Ag on the surface and crystal growth of AgBr are discussed, and a comparison with other theoretical results is given.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 559 (1988), S. 17-26 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Oxoaluminate KLi4[AlO4]Transparent and colourless single crystals of Kli4[AlO4] have been prepared for the first time by heating mixtures of Li5AlO4 and K2O in the ratio 1:5 [Ni-tube, 950°C, 50 d]. The structure determination [four-circle diffractometer, MoKα, 1699 of 2427 I0 (hkl), R = 7.41%, Rw = 4.3%] proves the monoclinic space group P21/c with a = 554.4(3), b = 1544.1(7), c = 1103.3(6) pm, β = 109.71(5)°, parameters see text. Characterizing are “isolated” AlO4 groups with symmetry nearly Td. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, have been calculated.
    Notes: Erstmals wurde KLi4[AlO4] durch Erhitzen innig verriebener Gemenge von Li5AlO4 und K2O im molaren Verhältnis 1:5 [Ni-Bömbchen, 950°C, 50 d] dargestellt. Wir erhielten farblose monokline Einkristalle (P21/c) mit a = 554,4(3), b = 1544,1(7), c = 1103,3(6) pm, β = 109,71(5)°.Die Struktur wurde mittels Vierkreisdiffraktometerdaten [MoKα, 1699 von 2427 I0(hkl), R = 7,41%, Rw = 4,3%] bestimmt, Parameter siehe Text. Charakteristisch sind “isolierte” AlO4-Gruppen, Symmetrie nahezu Td. Der Madelunganteil der Gitterenergie, MAPLE, und Effektive Koordinationszahlen, ECoN, diese über Mittlere Fiktive Ionenradien, MEFIR, wurden berechnet.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 564 (1988), S. 45-60 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel Oxoplumbates(II) with Isolated Anion Structure: Rb4[PbO3] and Cs4 [PbO3]For the first time Rb4[PbO3] have been prepared as single crystals. The structure determination (four-circle diffractometer data) [Rb4[PbO3]: 1818 I0 (hkl), MoKα, R = 6.49%, Rw = 6.83%, space group Pbca (a = 681.2(1), b = 1178.7(1), c = 1979,9(1) pm), Z = 8; Cs4[PbO3]: 3663 Io (hkl), AgKα, R = 11.35%, Rw = 9.82%, space group P21 (a = 1188.1(2), b = 734.4(1), c = 1176.2(2) pm, β = 111.52(2)°), Z = 4] proves in both cases the expected “isolated” [PbO3] groups. Comparing the oxides the arrangements of these groups shows surprising differences (see text). The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, have been calculated.
    Notes: Erstmals dargestellt wurden Rb4[PbO3] und Cs4[PbO3] in Form von Einkristallen. Nach der Strukturbestimmung mit Vierkreisdiffraktometerdaten [Rb4[PbO3]: 1818 I0 (hkl), Mokα, R = 6,49%, Rw = 6,83%, Raumgruppe Pbca (a = 681,2(1), b = 1178,7(1), c = 1979,9(1) pm), Z = 8; Cs4[PbO3]: 3663 Io (hkl), AgKα, R = 11,35%, Rw = 9,82%, Raumgruppe P21 (a = 1188,1(2), b = 734,4(1), c = 1176,2(2) pm, β = 111,52(2)°), Z = 4] liegen bei beiden Oxiden „isolierte“ [PbO3]-Gruppen von, deren Anordnung zueinander sich jedoch grundsätzlich unterscheidet, (Einzelheiten vgl. Text). Der Madelunganteil der Gitterenergie, MAPLE, und Effektive Koordinationszahlen, ECoN, werden angegeben.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 548 (1987), S. 165-174 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Oxoplumbates(IV): Ba2PbO4For the first time single crystals of Ba2PbO4 have been prepared by exchange reaction [BaPbO3: Li2O2 = 2:4; Ag-cylinder, Argon, quartz ampoule, 800°C, 30 d]. The structure determination [137 I0(hkl), fourcircle diffractometer PW 1100 (Fa. Philips), MoKα, R = 5.04%, Rw = 4.93%] confirms the space group I4/mmm with a = 430.08 and c = 1325.63 pm (K2NiF4-type, parameters s. text).
    Notes: Erstmals in Form von Einkristallen wurde Ba2PbO4 durch Austauschreaktion [BaPbO3: Li2O2 = 2:4; Ag-Bömbchen, Argon, Quarzampulle, 800°C, 30 d] dargestellt. Die Strukturaufklärung [137 I0(hkl), Vierkreisdiffraktometer PW 1100 (Fa. Philips), MoKα, R = 5,04%, Rw = 4,93%] belegt die Raumgruppe I4/mmm mit a = 430,08 und c = 1325,63 pm (K2NiF4-Typ, Parameter s. Text).
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...