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
  • 1
    Electronic Resource
    Electronic Resource
    Photorearrangement of azoxybenzene to 2-hydroxyazobenzene. Evidence for electrophilic substitution by oxygen (1977)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 99 (1977), S. 7986-7991 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00466a034
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The electronic structure and spectroscopy of V2 (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 3192-3200 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The electronic structure and spectroscopy of the vanadium dimer has been studied with semiempirical self-consistent field-configuration interaction calculations using the intermediate neglect of differential overlap Hamiltonian parameterized for spectroscopy (INDO/S) including spin–orbit coupling effects. An approximate configuration interaction (CI) treatment is designed based on correlation effects observed in CI calculations in small active spaces, and yields good agreement with experimental observations of state energies and spin-orbit splittings. The location of a 1Σg+ excited state isoconfigurational with the ground state was determined, and calls into question a previous assignment of an excited state observed near 1860 cm−1. The previously observed A 3Πu←X 3Σg− transition is assigned as a dδg←dπu promotion. In addition, an unassigned transition observed near 15 000 cm−1 has been assigned as B 3Σu−←X 3Σg−. Both this transition and the previously observed A′ 3Σu−←X 3Σg− transition are assigned as σu←σg promotions, in disagreement with previous assignments. A 1Σu+ state isoconfigurational with the A′ 3Σu− state is suggested as a candidate for an unassigned transition in the range 11 250–12 500 cm−1. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.480903
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ground state isoconfigurational mixing in the V2, VNb, and Nb2 molecules (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 2203-2213 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Ground state spin–orbit effects in the molecules V2, VNb, and Nb2 have been investigated using self-consistent field configuration interaction (SCF/CI) calculations based on the intermediate neglect of differential overlap Hamiltonian parameterized for optical spectroscopy (INDO/S). Accurate results for the spin–orbit splittings of the X 3Σ− ground state of each molecule were obtained using a CI treatment designed to isolate essential correlation of the ground state and the isoconfigurational 1Σ+ state causing the splittings. Energies computed for the 1Σ+ states are compared to energies obtained from simple two-state perturbative models. It is observed that the consideration of only two states is a large source of error. Previous assignment of a low-lying excited state observed for V2 as the 1Σg+ state is not supported. Additional results on excited states of VNb have also been obtained. A 3Σ−←X 3Σ− transition observed experimentally for VNb is assigned as a σ*←σ promotion, and the presence of a second excited 3Σ− state of VNb that has not been observed is suggested. An analysis of correlation effects in the INDO/S model is given based on a comparison of results obtained with the approximate essential correlation CI calculations and with larger restricted active space full CI calculations. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.482034
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Including dispersion in configuration interaction-singles calculations for the spectroscopy of chromophores in solution (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 7293-7299 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: In this paper we prove that a configuration interaction electronic structure calculation on a supermolecule that contains only single excitations includes dispersion interactions between the two subsystems when energy differences are taken between the Hartree–Fock (molecular orbital) ground state and low energy excited states in which single excitations dominate. This theorem is proven up to second order in perturbation theory. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481332
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Obituary (2000)
    Springer
    Theoretical chemistry accounts 104 (2000), S. 335-335 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002140000171
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Inner-shell Eigenvalues from valence orbital only calculations (1975)
    Springer
    Theoretical chemistry accounts 37 (1975), S. 47-65 
    Details
    ISSN: 1432-2234
    Keywords: Inner-shell eigenvalues ; X-ray photoelectron spectra ; ESCA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Methods are examined for calculating Inner-shell Eigenvalues from molecular orbital models which do not explicitly include core basis functions. If the “valence-orbital only” calculation is a good one, a rather straightforward method can be used to obtain core eigenvalues with a rms error of ±0.01 a.u. compared with ab-initio values. Even simpler methods can be used to reproduce trends among core eigenvalues. The AAMOM valence technique, and to a lesser extent, the INDO model, can be used to yield core eigenvalues for orbitals centered on carbon and nitrogen: for oxygen the agreement is poorer. Extended Hückel or Iterative Extended Hückel methods cannot be used for this purpose with any degree of confidence. Eigenvalues from ab-initio studies or from AAMOM and INDO can be used in assigning ionization processes (XPS) from orbitals localized on carbon and nitrogen: ionization processes from oxygen orbitals are not well treated. An attempt is made to explain this behaviour.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00549770
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Triplet states via intermediate neglect of differential overlap: Benzene, pyridine and the diazines (1976)
    Springer
    Theoretical chemistry accounts 42 (1976), S. 223-236 
    Details
    ISSN: 1432-2234
    Keywords: Triplet states, INDO calculations of ∼ ; Benzene ; Pyridine ; Diazines
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The intermediate neglect of differential overlap technique is modified and applied to the calculation of excited triplet states. The resulting method generally reproduces the transition energies of the better-classified observations within a rms error of 1000 cm−1. Trends are well reproduced, and the calculated orders ofn-π* and π-π* triplet states are in good accord with the experimental information to date. The method is applied to benzene and the azines. The lowest four triplet states of benzene are calculated in good accord with experiment. Pyridine is calculated to have an-π* triplet nearly degenerate with the lowest lying π-π* triplet, corroborating suggestions of Japar and Ramsay based on experimental information. A detailed analysis is made of the diazines, and assignments are suggested for the higher lying triplet states not yet classified or not yet observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00574445
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    An intermediate neglect of differential overlap theory for transition metal complexes: Fe, Co and Cu chlorides (1979)
    Springer
    Theoretical chemistry accounts 53 (1979), S. 21-54 
    Details
    ISSN: 1432-2234
    Keywords: INDO method for transition metals ; Copper chloride ; Iron chloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A complete Intermediate Neglect of Differential Overlap model suitable for the examination of transition metal complexes is described. The model is characterized by the inclusion of all the one-center exchange terms necessary for rotational invariance and accurate spectroscopic predictions, as well as an accurate description of integrals involving 3d atomic orbitals. The model is within the unrestricted Hartree-Fock formalism, and a method for spin purification is described. Problems with convergence of the self-consistent field are discussed, and a method that has been found successful in aiding the convergence is outlined. The model has been applied to many transition metal systems. In this article the results of calculations on the chlorides of Fe, Co and Cu are described. The results of these calculations are compared with experiment, and with the results of calculations by other methods.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00547605
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Perspective on “New developments in molecular orbital theory” (2000)
    Springer
    Theoretical chemistry accounts 103 (2000), S. 217-218 
    Details
    ISSN: 1432-2234
    Keywords: Key words: Roothaan equation – Roothaan–Hall – Hartree–Fock – Roothaan self-consistent field
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract. This paper reviews the title article by Clemens Roothaan and the huge impact that his paper has had in modern chemistry. In his paper Roothaan converts the molecular Schödinger equation into a matrix equation by systematically introducing the linear combination of atomic orbitals–molecular orbital approximation and by invoking the variational principle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002149900010
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    On the excited states ofp-quinones and an interpretation of the photocycloaddition ofp-quinones to alkenes (1977)
    Springer
    Theoretical chemistry accounts 45 (1977), S. 283-300 
    Details
    ISSN: 1432-2234
    Keywords: p-Quinones, photocycloaddition with alkenes ; Electronic structure ofp-quinones ; Oxetans from3 n, π* states ofp-quinones ; Cyclobutanes from3π, π* states ofp-quinones ; Spectra of quinones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A theoretical investigation is made of the electronic states ofp-benzoquinone (PBQ), methyl substituted PBQ's and 1,4-naphthoquinone (NQ). In accord with experiment, the lowest triplet state of PBQ is calculated to be3 B 1g (n, π*), while that for duroquinone (DQ) is3 B 3g (π, π*). The electron densities of these states are consistent with the hypothesis that3 n, π* states lead to oxetan formation and3π, π* states to cyclobutanes. It is predicted that trimethyl PBQ might form both adducts, as the two states are calculated to be nearly degenerate. The photochemistry of NQ is more complex. The lowest excited triplet state is calculated to be ofn, π* symmetry, in accord with experiment; however, several other states are predicted near in energy, and the photochemistry cannot be rationalized unambiguously.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00554537
    Library Location Call Number Volume/Issue/Year 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...