Density functional theory without the Born-Oppenheimer approximation. II. Green function techniques

Shigeta, Yasuteru; Nagao, Hidemi; Nishikawa, Kiyoshi; Yamaguchi, Kizashi

doi:10.1002/(sici)1097-461x(1999)75:4/5<875::aid-qua52>3.0.co;2-l

Cited by 22 publications

(12 citation statements)

References 18 publications

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“…Such an orbital approach, termed the nuclear orbital plus molecular orbital (NOMO) method, simultaneously determines nuclear and electronic wave functions without BO approximation by using the NOs and MOs. Recently, orbital approaches for the non‐BO problem has been studied in other groups as well 36–55. In principle, the NOMO treatment is capable of giving the exact solution for the non‐BO problem, as discussed in Section 2.…”

Section: Introductionmentioning

confidence: 99%

Nuclear orbital plus molecular orbital theory: Simultaneous determination of nuclear and electronic wave functions without Born–Oppenheimer approximation

Nakai

2007

Int J of Quantum Chemistry

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ABSTRACT:We review a recent development in a rigorous non-Born-Oppenheimer method, i.e., nuclear orbital plus molecular orbital (NOMO) method, which determines the nuclear and electronic wave functions simultaneously. The NOMO theory is an exact theory for the non-BO problem in principle; for example, full-configuration interaction formulation for a complete configuration space. Hartree-Fock (HF) equations for NOs and MOs are derived for practical calculations. The usage of Gaussian basis functions for NOs is discussed. We formulate the elimination of translational and rotational contaminations in the NOMO method. Further, many-body effect such as nucleus-nucleus (n-n), nucleuselectron (n-e), and electron-electron (e-e) correlations are investigated by applying the second-order Møller-Plesset perturbation theory to the NOMO method. The excited-state theories such as configuration interaction and generator coordinate methods are examined to describe not only electronic but also vibrational excited states.

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Section: Introductionmentioning

confidence: 99%

Nuclear orbital plus molecular orbital theory: Simultaneous determination of nuclear and electronic wave functions without Born–Oppenheimer approximation

Nakai

2007

Int J of Quantum Chemistry

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“…At first we adopted a generator coordinate method to estimate electronic and vibronic excited states, 22 and then reformulated by using non-BornOppenheimer density functional theory (NBO-DFT) 23 and Green's function theory. 24 Nakai and Tachikawa also derived the same methodology at almost the same time 34 and developed post self-consistent field methods. They referred to these methods as multicomponent molecular orbital (MCMO) or nuclear orbital plus molecular orbital (NOMO) method.…”

Section: Theoretical Development Of Quantum Effects Of Nucleimentioning

confidence: 99%

Molecular Theory Including Quantum Effects and Thermal Fluctuations

Shigeta

2009

Bulletin of the Chemical Society of Japan

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Recent progress in our theoretical developments and applications where thermal fluctuations and quantum effects are important are reviewed. We first show that motions of a confined atom coupled with a fullerene cage cause large thermal fluctuation of the effective charge on the confined atom and that the fluctuation is sensitive to applied temperature and the number of confined species. Second, two different approaches to treat nuclear quantum effects are discussed. One is nonBornOppenheimer (NBO) molecular theory, which is one of an extension of molecular orbital theory for electrons to nuclear motions. This method is suitable to describe static and stationary nuclear (vibrational) states so we apply this method to obtain vibrationally coupled electron density of a protonatable amino acid. We compare the obtained electron density through NBO treatment with conventional calculations. The other approach is referred as to quantum cumulant dynamics (QCD), which is a generalization of quantized Hamiltonian dynamics initially proposed by Prezhdo. This method is applied to vibrational analyses. The ordinary normal mode analysis (NMA) is extended to include quantum degrees of freedom based on QCD formalism, which gives a better description of the vibrational state, where ordinary NMA gives incorrect results. Vibrational frequencies of small molecules by the QCD simulation are compared with those by classical molecular dynamics (MD). It is found that QCD is superior to classical MD in that the results obtained by QCD are in good agreement with those by full quantum treatment. Finally the theoretical background of a real-space gridbased time-dependent density functional theory (RSTDDFT) is explained. This method is applied to solve a NBO problem by using an imaginary time propagator and electron dynamics driven by an off-resonant circularly polarized laser plus in addition to using a real time propagator. For the latter case, we investigate atom-centered dipole moment and induced current and detect the electronic fluctuation in a SiH 4 molecule after irradiation.

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“…Moreover, many theoretical papers have reported that the PT products differ in their chemical properties such as the critical point of metal‐insulator transition temperature ( T c ) 19 and electron conductance 20, 21. Improved understanding of the PT reactions between DNA bases may lead to the control of these properties.…”

Section: Introductionmentioning

confidence: 99%

Sequence dependent proton‐transfer reaction in stacked GC pair I: The possibility of proton‐transfer reactions

Matsui

Sato

Shigeta

2009

Int J of Quantum Chemistry

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ABSTRACT:We explored the possibilities of proton-transfer reactions between guanines (G) and cytosines (C) in stacking two GC pairs by means of density functional methods. There are two combinations of sequences, GC/GC (5Ј-dGpG-3Ј) and CG/GC (5Ј-dCpG-3Ј). We found that the simultaneous single proton transfer (SPT) in two base pairs, two independent double proton transfer (DPT), and continuous double SPT reactions strongly depend on the sequence of the DNA, because the SPT reaction occurs in specific sequences including CG/GC and the latter DPTs occur in those including GC/GC. The properties of the DPT products, such as effective charges, are almost the same as the original GC/GC, whereas the effective charges on G and C in the simultaneous SPT product become negative and positive in comparison with those in the original GC/GC. Coulomb attraction caused by the charge separation mainly contributes to the stability of the SPT product.

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Density functional theory without the Born-Oppenheimer approximation. II. Green function techniques

Cited by 22 publications

References 18 publications

Nuclear orbital plus molecular orbital theory: Simultaneous determination of nuclear and electronic wave functions without Born–Oppenheimer approximation

Nuclear orbital plus molecular orbital theory: Simultaneous determination of nuclear and electronic wave functions without Born–Oppenheimer approximation

Molecular Theory Including Quantum Effects and Thermal Fluctuations

Sequence dependent proton‐transfer reaction in stacked GC pair I: The possibility of proton‐transfer reactions

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