Library

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
Filter
  • Articles: DFG German National Licenses  (4)
  • Electronic Resource  (4)
  • 1995-1999  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Crystal, Molecular, and Electronic Structure of 1-Acetyl-indoline and Derivatives (1998)
    Springer
    Structural chemistry 9 (1998), S. 365-373 
    Details
    ISSN: 1572-9001
    Keywords: 1-Acetyl-indoline ; crystal structure ; electronic structure ; AM1 calculation ; CI calculation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The crystal and molecular structures of the following molecules have been determined: 1-acetyl-indoline, 1-acetyl-5-nitro-indoline, l-acetyl-5-nitro-7-bromo-indoline, 1-acetyl-5-bromo-7-nitroindoline, and l-acetyl-5-bromo-7-nitro-indol. Molecular orbital calculations are performed for these compounds and two related species.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022419111660
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A Structure-Activity Relationship Study of Lapachol and Some Derivatives of 1,4-Naphthoquinones Against Carcinosarcoma Walker 256 (1998)
    Springer
    Structural chemistry 9 (1998), S. 47-57 
    Details
    ISSN: 1572-9001
    Keywords: MNDO-AM1-SCF-MO ; Lapachol ; PCA-HCA-KNN-SIMCA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract AMI semiempirical molecular orbital calculations were carried out on lapachol and several derivatives of 1,4-naphthoquinone in order to investigate possible relationships between electronic structural parameters and activity against carcinosarcoma Walker 256 (W256). It was found that, among the calculated electronic indices, that the HOMO (highest occupied molecular orbital) coefficients for carbon atoms of the side-chain double bond have a significant influence in the activity, while the LUMO (lowest unoccupied molecular orbitals) apparently have no importance. Exploratory data analysis through hierarchical cluster (HCA) and principal component analysis (PCA) showed a clear separation of the active compounds from the inactive ones. The activity against W256 probably involves a mechanism wherein the quinone acts as a reducing agent through the participation of the π-electrons of the side-chain double bond. A classification study with respect to structure-activity using KNN (K-nearest neighbors) and SIMCA (soft independent modeling of class analogy), two established chemometric methods of pattern recognition, have been used to predict activity for a series of lapachol derivatives.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1022487632133
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    On the implicit integral character of Roothaan's expansion (1999)
    Springer
    The European physical journal 5 (1999), S. 375-380 
    Details
    ISSN: 1434-6079
    Keywords: PACS. 31.15.Ar Ab initio calculations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: The molecular generator coordinate Hartree-Fock method is reviewed. The connection between a quadrature solution of the generator coordinate Hartree-Fock equations and Roothaan's equations is stressed. The relation between linear expansion coefficients and generator coordinate weight functions is discussed and a numerical and analytical example is provided for the 1s orbital of the hydrogen atom represented as the integral transform of a Gaussian function. For the same example, the Gauss-Labatto quadrature is employed to emphasize the implicit integral character of Roothaan's equations. As a major conclusion, the interpretation that every LCAO calculation is actually performing integrations of the Griffin-Wheeler equations is advanced. Basis sets are therefore abscissas of the implicit quadrature used in the integration, whereas the linear coefficients automatically incorporate the corresponding weights. Subsequently, it is shown how to extract the generator coordinate weight function from the LCAO coefficients which has the advantage of being a characteristic of the physical system under study and not of the particular calculation being carried out. As such, basis set design becomes how to efficiently sample the weight function.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s100530050269
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Generator coordinate Hartree-Fock method applied to the choice of a contracted Gaussian basis for the second-row atoms (1997)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 63 (1997), S. 927-934 
    Details
    ISSN: 0020-7608
    Keywords: generator coordinate Hartree-Fock ; Gaussian basis sets ; second-row atoms ; diatomic molecules ; Hartree-Fock energies ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The generator coordinate Hartree-Fock (GCHF) method is employed as a criterion for the selection of a 18s12p Gaussian basis for the atoms Na-Ar. The role of the weight functions in the assessment of the numerical integration range of the GCHF equations is shown. The extended basis is then contracted to (10s6p) by a standard procedure and in combination with the previously contracted (7s5p) Gaussian basis for the atoms Li-Ne is enriched with polarization functions. This basis is tested for AlF, SiO, PN, BCl, and P2. The properties of interest were HF total energies, MP2 dipolar moments, bond distances, and dissociation energies. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 63: 927-934, 1997
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...