Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Call number: 09-NW:127
    Keywords: Electrons ; Many-body problem ; Density functionals
    Pages: xiii, 850 p. : ill.
    ISBN: 0792306414
    Signatur Availability
    09-NW:127 departmental collection or stack – please contact the library
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-2234
    Keywords: Key words: Electronic quenching ; Nonadiabatic coupling ; Diabatic states ; Conical intersection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract. The quenching of Li (1s 22p; 2P) to Li (1s 22s; 2S) by H2 is considered using coupled-cluster and multireference configuration-interaction techniques. C 2 v (2A1, 2B2) and C ∞ v (2Π,2Σ+) sections of the 12A′ and 22A′ potential energy surfaces are determined. The C 2 v portion of the 12A′−22A′ seam of conical intersection is studied. Perhaps the most significant finding is a surprising trifurcation of this seam into a portion with only C s symmetry and the aforementioned C 2 v portion. The adiabatic-to-diabatic state transformation is considered in the vicinity of the seam of conical intersection using both perturbation theory and the dipole moment operator. The 2B2 section of the 22A′ potential energy surface exhibits an exciplex in the general vicinity of the seam of conical intersection. The 2Π section of the 22A′ potential energy surface possesses a global minimum lying 1.86kcal/mol below the Li (2P)+H2 asymptote. A van der Waals-like minimum with C ∞ v symmetry was found on the 12A′ potential energy surface.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 94 (1991), S. 2910-2914 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The recently proposed method for practical density functional calculations is extended to the spin-decomposed electron densities. From given α- and β-spin electron densities ρα(r) and ρβ(r), local scaling transformations are used to generate their possible parent wave function Ψρ({xi}), where xi=(ri,σi) is the combined position-spin coordinate of electron i. The energy E[ρα,ρβ] associated with the given spin-decomposed densities is then defined as the Hamiltonian expectation value over the generated wave function Ψρ({xi}), and the densities ρα and ρβ are determined so as to minimize the energy functional E[ρα,ρβ]. An illustrative application is given for the ground-state Li atom within the unrestricted Hartree–Fock framework.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 115 (2001), S. 833-841 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The hydrogen bonding between benzonitrile and one and two water molecules is studied ab initio by means of a hybrid B3LYP density functional in conjunction with 6-31+G(d,p) and aug-cc-pVDZ basis sets. The strength of such hydrogen bonding is analyzed in terms of a magnitude of "window region" appearing in the infrared spectra of the studied complexes and experimentally measurable and also in terms of the shifts of the stretching mode of the triple CN bond of benzonitrile. The lower-energy portions of the potential energy surfaces in the neighborhoods of the stable complexes of benzonitrile with one and two water molecules are fully determined, and implications of their landscape on the large-amplitude dynamics of the water moiety around benzonitrile and comparison with experiments are elaborated. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 114 (2001), S. 7911-7917 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Ab initio molecular orbital calculations up to the coupled-cluster level with the aug-cc-pVQZ basis set allowed us to have a new look at the electron affinity of nitrous oxide (N2O) resulting in a detection of a new N2O− entity, and thereby a novel mechanism for the dissociative electron attachment process, N2O+e−→N2+O−. Addition of an electron to the linear N2O ground state (X 1Σ+) leads first to an open-chain bound anion which lies 25 kJ/mol above the neutral. Upon a cyclization of the open anion with an additional energy barrier of 25 kJ/mol, a cyclic anionic species is formed which is more stable than the open isomer and lies now, at most, 3 kJ/mol above the neutral ground state (the transition structure for cyclization being 50 kJ/mol above neutral N2O). The cyclic anionic species constitutes a weak complex between N2 and O− characterized by a binding energy of only 16 kJ/mol. The electronic structure of the anion complex is analyzed, a number of earlier experimental results are clarified and a resolution for the long-standing disagreement between experiment and theory around the electron affinity of N2O is proposed. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1572-8897
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mathematics
    Notes: Abstract The local-scaling transformation version of density functional theory is extended to the treatment of excited states. This is accomplished in the context of the super-particle formulation of Katriel [Int. J. Quant. Chem. 23(19$3)1767]. It is shown that for a given superparticle generating wave function, the energy density functional corresponding to the excited-state super-system may be explicitly constructed. The derivation of an Euler-Lagrange equation for the composite excited-state density is discussed. A preliminary calculation for the 21S state of helium is reported.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0020-7608
    Keywords: Liquid water ; H-bond pattern ; orientational defect ; water cluster ; “dangling” bond ; ab initio HF/6-311(d, p) calculation ; Chemistry ; Theoretical, Physical and Computational Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fifteen different structures of the water hexamer found ab initio within the 6-311G(d, p) basis set in the interval of 1.75 kcal/mol above the global minimum represent an unprecedented wide range of conformational plasticity of liquid water. The present work also provides the first ab initio demonstration of the existence of pentacoordinated water clusters of an orientational defect type and elaborates their properties.   © 1998 John Wiley & Sons, Inc. Int J Quant Chem 70: 831-853, 1998
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1089-7658
    Source: AIP Digital Archive
    Topics: Mathematics , Physics
    Notes: For an unknown non-negative distribution Ω(z), the corresponding Hankel transform F(k) is introduced. It is proposed to partition F(k) in such a way that each component satisfies a linear differential relation whose solution gives an approximate Hankel transform in terms of a given finite set of even moments. As a result, for a known finite set of even moments, the non-negative distribution Ω(z) is obtained in the form of a finite sum of the definite differential and integral forms of the Gaussian distributions.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The recently proposed method of density mapping between momentum and position spaces is applied to the ground state of the helium atom. The Kellner densities and wave functions are used as reference, and the Eckart densities γ(p) and ρ(r) are employed as test densities keeping their parent wave functions in blind. From the momentum density γ(p), the corresponding position density ργ(r) and the position moments 〈rn〉γ (−2≤n≤4) are generated within a few percent error. The inverse procedure generates the momentum density γρ(p) and the momentum moments 〈pn〉ρ (−2≤n≤4) from the position density ρ(r) with a better accuracy. Density-functional calculations are performed in a simplified manner and the energies close to the Hartree–Fock limit value are obtained.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 1108-1113 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Based on the theory of point transformations, a possible exact relationship between the atomic electron densities in momentum and position spaces is studied through the inverse mapping from the electron density to the N-electron wave function with an appropriate generator or reference N-electron wave function. The results are used to construct the ground-state energy density functional of atoms in momentum space.
    Type of Medium: Electronic Resource
    Signatur Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...