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  • 1
    Title: Reviews of modern quantum chemistry : a celebration of the contributions of R. G. Parr
    Contributer: Sen, Kali Das , Parr, Robert G. , Parr, Robert G.
    Publisher: Singapore [u.a.] :World Scientific
    ISBN: 981-02-4889-x
    Type of Medium: Book
    Language: English
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  • 2
    Book
    Book
    Oxford u.a. :Oxford University Pr.,
    Title: Density-functional theory of atoms and molecules; Vol. 16
    Author: Parr, Robert G.
    Contributer: Yang, Weitao
    Publisher: Oxford u.a. :Oxford University Pr.,
    Year of publication: 1989
    Pages: 333 S.
    Series Statement: International series of monographs on chemistry Vol. 16
    Type of Medium: Book
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  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 106 (1997), S. 5578-5586 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Based on functional expansion methods recently developed, the total energy of an atomic and molecular system is expanded in terms of its chemical potential (electronegativity), hardness, softness, Fukui function, response function, and so on, up to the second order. Expansions are given within the four basic ensembles in density functional theory: the canonical, grand canonical, isomorphic, and grand isomorphic ensembles. The formulas obtained provide explicit relations among the important quantities related to the chemical reactivity of a system, and they provide a means to calculate one quantity when others are known. Furthermore, a favorable viewpoint of the maximum hardness principle follows from these formulas. At fixed electron number, external potential and chemical potential, the global hardness should go to a maximum as the total energy approaches a minimum. Arguments for the second-order truncation are given. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 107 (1997), S. 3000-3006 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: New relations among reactivity descriptors are provided within the recently introduced modified isomorphic ensemble of density functional theory. In addition, expressions for the softness and hardness kernel are derived in the canonical, grand canonical, isomorphic, and grand isomorphic ensemble. There results a new definition for the local hardness, η(r)=[∂u(r)/∂N]σ=ησ−g(r), where g(r)=[∂υ(r)/∂N]σ and σ=ρ/N is the shape factor. This identifies the local hardness as a function measuring the response of the system's external potential to a perturbation in electron number at a constant shape factor. Furthermore, it is shown that one cannot represent both local softness and local hardness unambiguously with one representation. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Accounts of chemical research 26 (1993), S. 256-258 
    ISSN: 1520-4898
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 83 (1985), S. 2334-2336 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: As previously shown [M. Levy and J. P. Perdew, Phys. Rev. A (in press)], the customary Hohenberg–Kohn density functional, based on the universal functional F[ ρ], does not exhibit naively expected scaling properties. Namely, if ρλ=λ3ρ(λr) is the scaled density corresponding to ρ(r), the expected scaling, not satisfied, is T[ρλ]=λ2T[ρ] and V[ρλ]=λV[ρ], where T and V are the kinetic and potential energy components. By defining a new functional of ρ and λ, F[ ρ, λ], it is now shown how the naive scaling can be preserved. The definition is F[ρ(r), λ]=〈λ3N/2 Φminρλ (λr1... λrN)|Tˆ(r1...rN) +Vee(r1...rN)| λ3N/2Φminρλ(λr1...λrN)〉, where λ3N/2 Φminρλ(λr1... λrN) is that antisymmetric function Φ which yields ρλ(r)=λ3ρ(λr) and simultaneously minimizes 〈Φ|Tˆ(r1...rN) +λVee(r1...rN)|Φ〉. The corresponding variational principle is EvG.S.=Infλ, ρ(r){∫ drv(r) ρλ(r)+λ2T[ ρ(r)] +λVee[ ρ(r)]}, where EvG.S. is the ground-state energy for potential v(r). One is thus allowed to satisfy the virial theorem by optimum scaling just as if the naive scaling relations were correct for F[ ρ].
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 85 (1986), S. 3135-3135 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 82 (1985), S. 3307-3315 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Orthonormal orbitals systematically constructed from the electron density are employed to obtain various closed expressions for approximate atomic energy functionals. A three-dimensional generalization of a construction originally due to Harriman is proposed. Numerical assessments are made of several new density functionals by evaluating them using accurate Hartree–Fock densities and by solving the corresponing Euler equations for electron density. The molecular virial theorem is stated and proved in a form particularly suitable for density functional theory.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 84 (1986), S. 1696-1703 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Given a homonuclear diatomic molecule AB with an even number of electrons N in the state ψ. What is the state of atom A in the molecule? Using the lemma that 〈ψ||HA ||ψ〉/〈ψ||ψ〉≥E0A where HA is the Hamiltonian for atom A only, having NA =N/2 electrons, and E0A is the ground state energy of A, the following general definition is suggested and quantitatively tested for the hydrogen atom in the hydrogen molecule. Define N-electron functions ψA and ψB by ||ψ||2= 1/2 [||ψA||2+||ψB||2], ψA =ψ[1+F]1/2, and ψB =ψ[1−F]1/2, with ψA, ψB, and ψ all normalized and F a function symmetric with respect to electron interchange. Then ρ=ρA+ρB and F can be determined to minimize the promotion energy 〈ψA||HˆA||ψA〉−E0A. Calculations are performed for the H2 ground state and b3∑+u excited state, as functions R, employing accurate wave functions including correlation. For the ground state at the equilibrium internuclear distance, the promotion energy is found to be 0.0447 a.u. or 28 kcal/mol. The electron density for the atom in the molecule is examined, and extensions to heteronuclear and polyatomic molecules briefly discussed.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 84 (1986), S. 1704-1711 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A method based on first-order density matrices is proposed to define an atom in a molecule, which is in accord with a previously given definition using density functional theory. The promotion energy Ep is expressed in terms of a defined division function α(r). By minimizing Ep with respect to α(r), one can obtain α(r), by which an atom in a molecule is uniquely determined. It is shown that such an "atom'' satisfies a local virial theorem, depicted intuitively, Some other properties of the atom in a molecule are also discussed. Comparison is made with a definition due to Bader, and an approximate but simple approach to determine an atom in a molecule is proposed.
    Type of Medium: Electronic Resource
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