Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Cage molecules containing elements of groups V and VI. I. Structure determinations using simulated annealing (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 2942-2950 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Density functional calculations with simulated annealing have been performed to determine the structures and relative stabilities of stable isomers of seven-membered molecules containing elements of groups V (phosphorus, arsenic) and VI (sulfur, selenium, and tellurium). Particular attention is focused on structures related to P4S3 and P2S5, including the families PnAs4−nS3−mSem and P4SnTe3−n. We show that the bonding trends in all these molecules can be understood in terms of transferable bond energies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.461991
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Structure of phosphorus clusters using simulated annealing—P2 to P8 (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 6710-6721 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The geometries of low-lying isomers of phosphorus clusters P2 to P8 have been calculated using a density functional (DF) method, combined with molecular dynamics (MD) and simulated annealing techniques. The structures and vibration frequencies are in excellent agreement with experiment in those cases (P2, P4) where spectroscopic data are available. A roof-shaped tetramer is a prominent structural unit in low-lying states of P5, P6, P7, and P8. Contrary to widespread belief, the most stable isomer of P8 is not cubic, but the "wedge'' or "cradle'' structure found as a structural unit in violet (monoclinic, Hittorf) phosphorus. The energetic ordering and geometrical shapes of the P8 isomers show striking analogies to the corresponding valence-isoelectronic hydrocarbons (CH)8 cubane, cuneane, and 2,2':4,4'-bis-(bicyclobutyl). The bonding and structural trends in phosphorus clusters are discussed in detail.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.458306
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Structure of sulfur clusters using simulated annealing: S2 to S13 (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 6823-6835 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: The ground state geometries of sulfur clusters S2 to S13 have been calculated using a parameter-free density functional (DF) method, combined with molecular dynamics (MD) and simulated annealing techniques. The results are in good agreement with available experimental data, and should provide reliable predictions where detailed measurements are lacking (n=3,4,5,9). The bonding trends are discussed in detail. The MD-DF approach is particularly valuable in larger clusters, where there are many local energy minima with comparable energies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.455356
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Cage molecules containing elements of groups V and VI. II. Molecular dynamics study of P4S3 and P3−7 (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 2951-2952 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Molecular dynamics (MD) simulations have been performed to determine the stability of the cagelike structure of the seven-membered systems P3−7 and P4S3. In both cases the cage structure remains intact during simulations of several picoseconds. However, fluxional behavior of the P3−7 trianion could be observed directly, whereas no isomerization took place in P4S3.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.461992
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Structure of phosphorus clusters using simulated annealing. II. P9, P10, P11, anions P2−4, P2−10, P3−11, and cations P+n to n=11 (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 96 (1992), S. 7564-7572 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Previous calculations on the structures of isomers of phosphorus clusters P2 to P8 [density functional calculations with simulated annealing (SA), J. Chem. Phys. 92, 6710 (1990)] have been extended to P9, P10, and P11. The tendency of phosphorus to form tubular structures is already evident in clusters of this size. We have also performed calculations on additional isomers of the hexamer P6, positive ions up to P+11, and the P2−4, P2−10, and P3−11 anions. Ionization energies agree well with available measurements [P1 to P4] and show trends that can be correlated with the structures and the measured relative abundances of the ions. The calculated structure of P3−11 agrees very well with x-ray diffraction data, and we observe isomerization in P9 resulting from charge transfer. A simplified SA scheme using a linear combination of atomic orbitals (LCAO) has been used to aid the analysis of the results.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.462408
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Sulfur and selenium helices: Structure and electronic properties (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 2652-2658 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Density functional calculations of the energy surfaces of infinite helical chains of selenium have been performed for a wide range of geometries using the parameter-free local density approximation. The results are compared with our earlier calculations for the sulfur helix S∞ for which the calculated ground state geometry is in good agreement with experiment. The energy surfaces of both molecules are flat over large regions of configuration space—consistent with the extreme flexibility of these molecules—and are characterized by a variety of local minima and saddle points. Stretching each molecule results in planar zig-zag and linear geometries with overlapping conduction bands. The energy differences between helical and planar minima are small (∼0.2 eV).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.453992
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Simulated annealing study of neutral and charged clusters: Aln and Gan (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 99 (1993), S. 1194-1206 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Density functional calculations with simulated annealing have been performed for clusters of aluminum Aln and gallium Gan up to n=10. There are many local minima in the energy surfaces, with a rich variety of structures and spin multiplicities. With increasing cluster size we find transitions from planar to nonplanar structures at n=5, and to states with minimum spin degeneracy at n=6. Isomers (n≥5) with buckled planar structures reminiscent of the layers in crystalline α-gallium are generally less stable than "three-dimensional'' isomers. All structures show regular patterns of bond and dihedral angles. Systematic differences between Al and Ga clusters—bonds in the latter are shorter and bond angles closer to 90°—can be understood in terms of atomic properties. Trends in binding and ionization energies are compared with experiment and with the predictions of other calculations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.465363
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Isomers of S7O2: A Simulated Annealing Study (1994)
    s.l. : American Chemical Society
    Inorganic chemistry 33 (1994), S. 1340-1343 
    Details
    ISSN: 1520-510X
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/ic00085a021
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Structure, bonding, and dynamics in heterocyclic sulfur-selenium molecules, SexSy (1990)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 112 (1990), S. 2590-2596 
    Details
    ISSN: 1520-5126
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/ja00163a018
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Density functional study of phosphorus and arsenic clusters using local and nonlocal energy functionals (1994)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 100 (1994), S. 4941-4946 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Previous calculations of the structures of isomers of phosphorus clusters up to P11 (density functional calculations with simulated annealing, local spin density approximation to the exchange-correlation energy) have been extended to arsenic clusters. The structures of Asn clusters are characterized by an almost uniform expansion (∼ 9%) of the corresponding Pn isomers. All cluster isomers have also been studied using a nonlocal, gradient corrected (Becke–Perdew) energy functional. While the structures are almost unchanged, there are significant improvements in the cohesive energies of all clusters. We present a simple picture to show that the improvements arise from contributions both in the atoms and near the "surface'' of the clusters.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.467213
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...