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Nambu Shinkoh

  (南部 伸孝)

Profile Information

Affiliation
Professor, Faculty of Science and Technology, Department of Materials and Life Sciences, Sophia University
Degree
博士（理学）(慶應義塾大学)
Contact information
shinkoh.nanbusophia.ac.jp
Other name(s) (e.g. nickname)
Shinkoh NANBU
Researcher number
00249955
J-GLOBAL ID
200901062366264730
researchmap Member ID
1000144738

April,1988-March,1994
Doctoral research in Keio University; the research title is “Theoretical studies of the potential energy surfaces for the excited statea and the reaction dynamics.” Prof. Suehiro IWATA is a supervisor for the thesis.
April,1994-March,1997
The idea of molecular switching was proposed with Prof. Hiroki NAKAMURA in IMS and Prof. F. O. Goodman in Waterloo university. The titile of the correspoinding paper is “Molecular switching in one-dimensional finite periodic nonadiabatic tunneling potential systems.”
September,1995-March,2002
The highly vibrational states were theoretically explored with Prof. Mutsumi AOYAGI in Kyushu university.
June,1999-December,1999
The reaction dynamics, especially the idea of transition wavepacket method was developed in Argonne national laboratory. The host professors are Prof. Stephen K. GRAY and Albert F. WAGNER.
April,1994-present
My research concerns mostly the development and application of methods to determine and analyze quantum mechanics of chemical reactions. One of my recent interests related to the quantum phenomena is non-adiabatic transition which could occur in various fields, such as chemistry, physics, biology, and economy. I am also interested in high performance computing (HPC), because I believe that the HPC would provide us “break-through” on our new science.

2015-2016 Chemistry division director in Graduate School of Science and Technology
2012-2013 A member of Educational affairs committee
2010-2012 Chemistry division director in Graduate School of Science and Technology
2012 Promotion committee in Faculty of Science and Technology
2012- Research member in Graduate School of Global Environmental Studies

My research concerns mostly the development and application of methods to determine and analyze quantum mechanics of chemical reactions. One of my recent interests related to the quantum phenomena is non-adiabatic transition which could occur in various fields, such as chemistry, physics, biology, and economy. I am also interested in high performance computing (HPC), because I believe that the HPC would provide us “break-through” on our new science. My actual research project is as follows;
(i) Quantum and semi-classical wavepacket dynamics – photo-dissociation process and reactive scattering,
(ii) Molecular switching – a new proposal of hydrogen encapsulation with an aggressive use of non-adiabatic phenomena,
(iii) Rigorous theoretical calculation for ro-vibrational motions of tri-atomic systems – including Coriolis coulping and Renner-Teller coupling,
(iv) Theoretical determination of isotopic fractionation constants, and so on.

(Subject of research)
Photo-chemical reaction in condensed phase

Research Interests

 11

Research Areas

 3

Research History

 4

Education

 3

Awards

 2

Papers

 131
  • Zhi-Hong Wang, Tsuneo Urisu, Shinkoh Nanbu, Jun Maki, G. Ranga Rao, Mutsumi Aoyagi, Hidekazu Watanabe, Kenta Ooi
    Physical Review B - Condensed Matter and Materials Physics, 69(4), Jan 21, 2004  Peer-reviewed
    Oxidation of Si(100) surfaces by H2O has been investigated on 2H+H2O/Si(100)−(2×1), H2O+Si(100)−(2×1), as well as H2O+H/Si(100)−(2×1) systems by infrared reflection absorption spectroscopy using CoSi2 buried metal layer substrates (BML-IRRAS). Three pairs of doublet bands assigned to the scissoring modes of adjacent and isolated SiH2 with zero, one, and two inserted back-bond oxygen atoms, respectively, have been reported. This report also has clearly shown the unique high sensitivity of BML-IRRAS for the perpendicular components in the fingerprint region, compared to the multiple internal reflection and the external transmission arrangements. Oxidation mechanisms have been proposed. In the 2H+H2O/Si(100) −(2×1) system, oxygen insertion into the back bond occurs easily. In the H2O+H/Si(100) system, however, the tunneling effect is important to reach the oxygen inserted state. © 2004 The American Physical Society.
  • H Watanabe, S Nanbu, ZH Wang, J Maki, T Urisu, M Aoyagi, K Ooi
    CHEMICAL PHYSICS LETTERS, 383(5-6) 523-527, Jan, 2004  
    The reaction paths are analyzed, by an ab initio molecular orbital method, for the surface reaction systems 2H + H2O/Si(100)-(2 x 1) and H2O + H/Si(100)-(2 x 1), in which SiH2 Species with one or two oxygen atom-inserted back bonds have been observed as stable reaction products. The following results are obtained: The initial energy for the former system is 87.97 kJ/mol higher than the highest transition state energies with the HF/6-31 +G* level. In the latter system, the highest transition state is located 175.66 kJ/ mol higher than the initial energy, and tunneling effect plays an important role. (C) 2003 Elsevier B.V. All rights reserved.
  • Zhi-Hong Wang, Tsuneo Urisu, Shinkoh Nanbu, Jun Maki, G. Rao, Mutsumi Aoyagi, Hidekazu Watanabe, Kenta Ooi
    Physical Review B, 69(4) 045309, Jan, 2004  
  • Ikuo Tokue, Katsuyoshi Yamasaki, Shinkoh Nanbu
    Journal of Chemical Physics, 119(12) 5874-5881, Sep 22, 2003  
    The molecular orbital (MO) configuration interaction (CI) method was used to obtain the potential energy surfaces (PES) of H2S(X̃) and H2S+(X̃,Ã). Quantum vibrational calculations using the PESs were used to obtain the Franck-Condon factors (FCF). Studies showed that the H2S+(X̃) state populated the vibrational ground state since its bending geometry was almost equal to that of H2S(X̃).
  • Tokue, I, K Yamasaki, S Nanbu
    JOURNAL OF CHEMICAL PHYSICS, 119(12) 5882-5888, Sep, 2003  
    Emissions in the 200-750 nm region produced by the collision of He-*(2 S-3) with H2S were studied under single-collision conditions. The hydrogen Balmer lines and the SH+(A (3)Pi-X (3)Sigma(-)) and H2S+( (A) over tilde (2)A(1)-(X) over tilde B-2(1)) bands were assigned. The total emission cross section (sigma(em)) was evaluated to be (1.7+/-0.3)x10(-20) m(2) at a collision energy of 150 meV. The sigma(em)s of the SH+(A-X) and H2S+((A) over tilde-(X) over tilde) bands decreased with increase in the collision energy in the 115-200 meV range, indicating that attractive forces are effective for the incident channels with regard to the formation of these species. The rotational distribution of SH+(A (3)Pi,nu(')=0) is represented by a Boltzmann temperature of 870+/-80 K. The H2S+(A (2)A(1)-X B-2(1)) emission, which was assigned for the first time in the Penning ionization of H2S, primarily consists of the bending progressions. The internal populations of H2S+(A) were analyzed using the vibrational energies and Einstein's A coefficients calculated in this study. The details of the calculation and derived spectroscopic constants are reported in the accompanying paper, Paper I. The populations obtained for the bending vibration (nu(2)(')) of H2S+((A) over tilde) show an inverted distribution with a peak at nu(2)(')=3. This distribution is shifted lower compared that with a peak at nu(2)(')=4-5 observed by He-*(2 S-3) Penning ionization electron spectroscopy and that with a peak at nu(2)(')=6-7 predicted by the theoretical Franck-Condon factors for the H2S((X) over tilde)-H2S+((A) over tilde) ionization. The origin of the difference is discussed concerning the formation mechanism of H2S+((A) over tilde (2)A(1)). (C) 2003 American Institute of Physics.
  • Tokue, I, K Yamasaki, S Nanbu
    JOURNAL OF CHEMICAL PHYSICS, 119(12) 5874-5881, Sep, 2003  
    In order to elucidate the ionization dynamics, in particular the vibrational distribution, of H2S+(A) produced by the Penning ionization of H2S with He-*(2 S-3) atoms, the Franck-Condon factors (FCFs) were presented for the H2S(X)-->H2S+(X,A) ionization and the H2S+(A-X) transition, and Einstein's A coefficients were presented for the latter transition. The FCFs were obtained by quantum vibrational calculations using the global potential energy surfaces (PESs) of H2S(X (1)A(1)) and H2S+(X B-2(1),A (2)A(1),B B-2(2)) electronic states. The global PESs were determined by the multireference configuration interaction calculations with the Davidson correction and the interpolant moving least squares method combined with the Shepard interpolation. The obtained FCFs exhibit that the H2S+(X) state primarily populates the vibrational ground state since its equilibrium geometry is almost equal to that of H2S(X), while the bending mode (nu(2)) is strongly enhanced for the H2S+(A) state; the maximum in the population is around nu(2)=6-7. In the same manner, the bending progressions are expected to consist of the great part of the H2S+(A-X) emission. A detailed comparison with the experimental study for this system is reported in the accompanying paper, Paper II. (C) 2003 American Institute of Physics.
  • S Minamino, JI Choe, SK Chang, F Mizutani, S Nanbu
    CHEMICAL PHYSICS LETTERS, 374(5-6) 572-576, Jun, 2003  
    Theoretical infrared (IR) absorption spectra were calculated for p-tert-butylcalix[4]crown-6-ether (1) in the cone conformer and its ethyl ammonium complex. The IR spectra were obtained by restricted Hartree-Fock (RHF) calculations with the 6-31G basis set. For the purpose of an absorption band assignment on the host molecule, guest molecule, and complexes thereof, we discussed a way to distinguish a specific molecule by comparing the calculated vibrational spectra. The theoretical result for the host molecule I and its ethyl ammonium complex were preliminarily compared with the experimental result, and found that the calculated result agrees well with the features of the experimental spectra. (C) 2003 Elsevier Science B.V. All rights reserved.
  • JI Choe, SK Chang, M Satoshi, S Nanbu
    BULLETIN OF THE KOREAN CHEMICAL SOCIETY, 24(1) 75-80, Jan, 2003  
    The structures and complexation energies of penta-O-alkylated 1b and penta-O-tert-butyl ester le of p-tert-butylcalix[5]arene and their simplified structures (2b and 2e) toward a series of alkyl ammonium guests have been calculated by a semi-empirical AM I method. For AM I calculations, complexation efficiencies of the simplified host 2e are very similar to the values of host le. The complexes of simplified host;2e with alkyl ammonium ions also have been optimized by ab initio HF/6-31G method. The calculated complexation efficiencies for 2e by ab initio method have been found to be bigger in magnitude than the values obtained by AMI calculations for linear alkyl ammonium guests. Calculation results show that all of the calix[5]aryl derivatives investigated in this study have much better complexation ability toward ammonium cation without alkyl group compared with other alkyl ammonium guests. Ab initio calculations also well duplicate the molecular discriminating behaviors of calix[5]arene derivative 2e between butyl ammonium ions: n-BuNH3+ > iso-BuNH3+ > sec-BuNH3+> tert-BuNH3+.
  • NANBU SHINKOH
    Annual Review, Jan, 2003  
  • Hideyuki Kamisaka, Hiroki Nakamura, Shinkoh Nanbu, Mutsumi Aoyagi, Wensheng Bian, Kiyoshi Tanaka
    Journal of Theoretical and Computational Chemistry, 1(2) 285-293, Oct, 2002  
  • KAMISAKA HIDEYUKI, NAKAMURA HIROKI, NANBU SHINKOH, AOYAGI MUTSUMI, BIAN WENSHENG, TANAKA KIYOSHI
    Journal of Theoretical and Computational Chemistry, 1(2) 275-284, Oct, 2002  
  • NANBU SHINKOH, AOYAGI MUTSUMI, KAMISAKA HIDEYUKI, NAKAMURA HIROKI, BIAN WENSHENG, TANAKA KYOSHI
    Journal of Theoretical and Computational Chemistry, 1(2) 263-273, Oct, 2002  
  • Kensuke Harada, Keiichi Tanaka, Takehiko Tanaka, Shinkoh Nanbu, Mutsumi Aoyagi
    The Journal of Chemical Physics, 117(15) 7041-7050, Jul, 2002  
  • Tokue, I, H Tanaka, K Yamasaki, S Nanbu
    JOURNAL OF PHYSICAL CHEMISTRY A, 106(25) 6068-6074, Jun, 2002  
    He(2(3)S) Penning ionization of HCl and HBr leading to HCl+(A) and HBr+(A) has been studied optically by using a crossed-beam apparatus. The ratios of the vibrational population, P-nu/P-0 (nu' = 2 and 3) of HCl+(A) and P-1/P-0 of HBr+(A), increase with the collision energy in the region of 120-200 meV. The rotational distributions of HCI+(A, nu'= 0) and HBr+(A, nu'= 0) can be represented by a double-Boltzmann distribution; the temperatures are 200 +/- 50 and 700 +/- 80 K for HCI+(A, nu'= 0) and 250 +/- 50 and 1200 +/- 200 K for HBrl(A) and are nearly independent of the collision energy. The bimodal rotational distributions suggest that at least two processes contribute to formation of these ions. The model potential surface calculated for He*(Li) + HCl as the entrance channel is nearly isotropic and shows a shallow well of about 20 meV, whereas the surface for He + HCI+(A) as the exit channel is anisotropic and shows a deep minimum of 250 meV in the He-H-Cl collinear direction. Dynamical effects of the anisotropic attractive structure in the exit surface are proposed to account for the observed results.
  • JI Choe, SK Chang, S Nanbu
    BULLETIN OF THE KOREAN CHEMICAL SOCIETY, 23(6) 891-895, Jun, 2002  
    The structures and energies of p-tent-butylcalix[4]crown-6-ether (1) in various conformers and their alkyl ammonium complexes have been calculated by ab initio HF/6-31G quantum mechanics method. We have tried to obtain the relative affinity of partial-cone and 1,3-alternate conformers of 1 for alkyl ammonium guests by comparison with its cone-shaped analogue. We have also calculated the relative complexation efficiency of these host-guest complexes focusing on the binding sites of crown-6-ether moiety or benzene-rings pocket of the host molecule 1. These calculations revealed that the crown moiety has better complexation efficiency than upper rim part of calix[4]arene that is in similar trend to the cone-shaped complexes.
  • J Ouyang, K Yakushi, T Kinoshita, N Nanbu, M Aoyagi, Y Misaki, K Tanaka
    SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, 58(8) 1643-1656, Jun, 2002  
    Infrared and Raman spectra of 2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene (BDT-TTP) and 1,3,4,6-tetrathiapentalene-2,5-dione (TTP-DO) are reported. The vibrational modes of TTP-DO are assigned with the aid of the depolarization ratio of solution Raman spectra, polarized reflection spectra and polarized Raman spectra. A D-2h symmetry is assumed for the BDT-TTP molecule and its in-plane fundamental vibrations are assigned with the aid of the polarization ratio and the correlation with TTP-DO, tetrathiafulvalene (TTF), tetramethyl tetrathiafulvalene (TMTTF) and bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF). Normal coordinate calculation with a modified internal valence force field was carried out for the in-plane fundamental vibrations of TTP-DO and BDT-TTP. Ab initio calculations of the normal modes of BDT-TTP0 and BDT-TTP+ are compared with the empirical analysis. (C) 2002 Elsevier Science B.V. All rights reserved.
  • JI Choe, SK Chang, SW Ham, S Nanbu, M Aoyagi
    BULLETIN OF THE KOREAN CHEMICAL SOCIETY, 22(11) 1248-1254, Nov, 2001  
    The conformations and energies of p-tert-butylcalix[4]crown-6-ether (1) and its alkyl ammonium complexes have been calculated by ab initio HF/6-31G quantum mechanics method. The cone conformation was found to be most stable for free host 1. We have determined the binding site of these host-guest complexes focusing on the crown-6-ether or p-tert-butylcalix[4]arene pocket of the cone conformation of host molecule 1. The primary binding site of host 1 for the recognition of alkyl ammonium guests was confirmed to be the central part of the crown moiety of cone conformation. The complexation energy calculations revealed that the ammonium cation without alkyl group showed the highest complexation efficiency when combined with host 1, that is in satisfactory agreement with the experimental results.
  • C. Miron, M. Simon, P. Morin, NANBU SHINKOH, N. Kosugi, S. L. Sorensen, A. Naves, de Brito, M. N. Piancastelli, O. Björneholm, R. Feifel, M. Bässler, S. Svensson
    The Journal of Chemical Physics, 115(2) 864-868, Jan, 2001  
  • S Skokov, T Tsuchida, S Nanbu, JM Bowman, SK Gray
    JOURNAL OF CHEMICAL PHYSICS, 113(1) 227-236, Jul, 2000  
    Wave packet calculations, using direct and damped-L-2 real propagation methods, of initial state-resolved and cumulative reaction probabilities for the O(P-3)+HCl((1)Sigma(+))--> OH((2)Pi)+Cl(P-2) reaction are reported. Results are obtained using the recently developed "S4" potential surface of Ramachandran and co-workers and, for comparison, the earlier Koizumi, Schatz, and Gordon (KSG) potential energy surface. Most calculations are for total angular momentum J=0, although some J > 0 centrifugal sudden results are also obtained. The thermal rate constant and the rate constant for HCl(v=1) are obtained from the J=0 cumulative reaction probability and J-K-shifting, using standard transition-state rotation constants. This type of shifting is justified by examining limited centrifugal sudden calculations. The S4 surface is shown to yield some surprising results. For example, despite a significantly higher ground state adiabatic barrier than the KSG surface, the thermal rate constant is not significantly different from one obtained with the KSG surface, although the one for the vibrationally excited HCl is. (C) 2000 American Institute of Physics. [S0021- 9606(00)30824-8].
  • S Nanbu, SK Gray, T Kinoshita, M Aoyagi
    JOURNAL OF CHEMICAL PHYSICS, 112(13) 5866-5876, Apr, 2000  
    Global, ab initio potential energy surfaces for HCP in its ground 1 (1)Sigma(+) (1 (1)A') and low-lying excited 1 (1)A ", 2 (1)A', and 1 (1)Delta(2 (1)A ") electronic states are determined. The multireference configuration interaction method at the double zeta with polarization basis set level is used, although some calculations augmented with diffuse functions are also discussed. Numerous quantum mechanical rovibrational states are then obtained for these surfaces, with emphasis on those corresponding to excited electronic state levels which have not been studied theoretically before. The results agree reasonably well with available experimental data for the 1 (1)A " state. Furthermore, the presence of certain local minima on the 1 (1)A " and 2 (1)A' surfaces leads to one new series of levels on the 1 (1)A " surface, and two new series on the 2 (1)A' surface. (C) 2000 American Institute of Physics. [S0021-9606(00)30413-5].
  • T Nishikawa, T Kinoshita, S Nanbu, M Aoyagi
    JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM, 461 453-461, Apr, 1999  
    The C-2, D-2, and D-2d isomers of C-84 fullerene were investigated by ab initio molecular orbital calculations. Optimized geometries, relative stabilities, and Vibrational spectra of 11 isomers are determined by Hartree-Fock calculations with STO-3G, 3-21G, and D95V basis sets. For the purpose of an assignment on the C-84 structures, we discussed a way to distinguish a specific isomer by comparing the calculated vibrational spectra. (C) 1999 Elsevier Science B.V. All rights reserved.
  • T Suzuki, H Katayanagi, S Nanbu, M Aoyagi
    JOURNAL OF CHEMICAL PHYSICS, 109(14) 5778-5794, Oct, 1998  
    The speed, angular, and alignment distributions of S(D-1(2)) atoms from the ultraviolet photodissociation of OCS have been measured by a photofragment imaging technique. From the excitation wavelength dependence of the scattering distribution of S(D-1(2)), the excited slates accessed by photoabsorption were assigned to the A' Renner-Teller component of the (1)Delta and the A"((1)Sigma(-)) states. It was found that the dissociation from the A' state gives rise to high- and low-speed fragments, while the A" slate only provides the high-speed fragment. In order to elucidate the dissociation dynamics, in particular the bimodal speed distribution of S atoms, two-dimensional potential energy surfaces of OCS were calculated fur the C-S stretch and bending coordinates by nb initio molecular orbital (MO) configuration interaction (CI) method. Conical intersections of (1)Delta and (1)Sigma(-) with (1)Pi were found as adiabatic dissociation pathways. Wave packet calculations on these adiabatic surfaces, however, did not reproduce the low-speed component of S(D-1(2)) fragments. The discrepancy regarding the slow S atoms was attributed to the dissociation induced by nonadiabatic transition from A'((1)Delta) to A'((1)Sigma(+)) in the bending coordinate. This hypothesis was confirmed by wave packet calculations including nonadiabatic transitions. The slow recoil speed of S atoms in the nonadiabatic dissociation channel is due to more efficient conversion of bending energy into CO rotation than the adiabatic dissociation on the upper slate surface. By analyzing the experimental data, taking into account the alignment of S(D-1(2)) atoms, we determined the yield of the nonadiabatic transition from the A'((1)Delta) to the ground states to be 0.31 in the dissociation at 223 nm. Our theoretical model has predicted a prominent structure in the absorption spectrum due to a Feshbach resonance in dissociation, while an action spectrum of jet-cooled OCS measured by monitoring S(D-1(2)) exhibited only broad structure, indicating the limitation of our model calculations. (C) 1998 American Institute of Physics.
  • S Nanbu, H Nakamura, FO Goodman
    JOURNAL OF CHEMICAL PHYSICS, 107(14) 5445-5459, Oct, 1997  
    A new idea of molecular switching is presented, The idea is based on the intriguing phenomenon of complete reflection, which occurs in a two-state potential curve crossing of the nonadiabatic tunneling type. Complete switching of transmission is theoretically possible in one-dimensional systems by introducing impurities in the system. The basic semiclassical theory is presented, and the phenomenon of complete reflection is clearly interpreted and numerically demonstrated, An idea of an energy filter to facilitate the switching efficiently is also introduced. The possibility of bound states in the continuum is also clarified, This new molecular switching is numerically realized by the wave packet propagation. (C) 1997 American Institute of Physics.
  • S Nanbu, S Minamino, M Aoyagi
    JOURNAL OF CHEMICAL PHYSICS, 106(19) 8073-8083, May, 1997  
    Potential energy surfaces for the ground and two low-lying electronically excited states of CaNC/ CaCN, are calculated using the ab initio molecular orbital (MO) configuration interaction (CI) method. The absorption and emission spectra of the system are computed by performing time-dependent quantum dynamical calculations on these surfaces. The most stable geometries for the two lowest lying 1(2) Sigma(+) and 1(2) Pi electronic states correspond to the calcium isocyanide (CaNC) structure. These two states are characterized by ionic bonding and the potential energy curves along the bending coordinate are relatively isotropic. The result of our wave packet dynamics shows that the characteristics of the experimental spectra observed by the laser-induced fluorescence spectroscopy can be explained by the Renner-Teller splitting. (C) 1997 American Institute of Physics.
  • S NANBU, M GOMYO, S IWATA
    CHEMICAL PHYSICS, 184(1-3) 97-106, Jun, 1994  
    Potential energy surfaces for electronic ground and four excited states of the fluoroformyl radial, FCO, were calculated with the ab initio molecular orbital (MO) configuration interaction (CI) method. The electronic transition related with progressions I and II in the photoabsorption spectra observed by Jacox [J. Mol. Spectry. 80 (1980) 257] was found to be the 1 2A''(1 2PI) <-- 1 2A' transition, and the pathway of the photodissociation, FCO (1 2A') + hnu --> CO(1SIGMA+) + F(2P), with a threshold near 280 nm, was clarified.
  • Umpei Nagashima, Shinkoh Nanbu, Fumio Nishimoto, Nobuhiro Fukusima
    IPSJ SIG technical reports, 93(33) 29-36, Apr, 1993  
  • M HIYAMA, S NANBU, S IWATA
    CHEMICAL PHYSICS LETTERS, 192(5-6) 443-450, May, 1992  
    The rare gas-alkali molecular ions, (HeLi)+, (HeNa)+ and (HeK)+, are investigated with the ab initio MO CI method. The first excited singlet state of the three diatomic ions is the charge-transfer 2 1-SIGMA+ state and it forms an excimer. The simulated theoretical emission spectrum from the first excited state of HeLi+, HeNa+, and HeK+ has a single narrow peak at 66.97, 65.50 and 63.04 nm (from v' = 0), respectively. The corresponding peaks observed by Petkau et al. are 66.78, 65.76, and 63.82 nm. Because a competitive pathway is found in the excited singlet state of HeK+, HeNa+ is the rare-gas-alkali-metal diatomic ion which shows the shortest wavelength emission among these possible candidates for VUV lasing systems. The calculated lifetimes of HeLi+. HeNa+ and HeK+ are 2.7, 2.8 and 3.3 ns, respectively.
  • S NANBU, S IWATA
    JOURNAL OF PHYSICAL CHEMISTRY, 96(5) 2103-2111, Mar, 1992  
    Potential energy surfaces for electronic ground and excited states of HOCl, which are related to the experimentally observed photoabsorption between 400 and 200 nm, were calculated with the ab initio molecular orbital (MO) configuration interaction (CI) method. The transition dipole moment surfaces between these states were also calculated. Two types of model calculations were carried out for evaluation of the theoretical photodissociation cross section. Theoretical spectra exhibit two peaks at about 335 and 245 nm. They are in better agreement with the experimental results than those in the previous study (Nambu, S.; et al. Chem. Phys. 1989, 135, 75). The present calculation supports the assumption that the HOCl molecule in the stratosphere may contribute to ozone depletion. The rotational state distributions of the product OH(2-PI) were explored with classical trajectory calculations. The rotational state distributions are dependent on the excited state.
  • Suehiro Iwata, Shinkoh Nanbu, Hideki Kitajima
    The Journal of Chemical Physics, 94(5) 3707-3714, 1991  
    Two of the ionic rare-gas alkali molecules, (Ne+Li)+ and (Ar+Li)+, were studied with ab initio calculations. The first and second excited singlet states 2 1Σ+ and 1 1Π of both ions form excimers. The simulated emission spectrum from 2 1Σ+ of NeLi+ peaks at 78.3 nm, and that from 1 1Π peaks at 78.5 nm, while the recently observed experimental peak is 80.3 nm. The theoretical spectral profile is also in good agreement with the experimental one. The radiative lifetimes of the corresponding excited states (υ′ = 0) are 2.6 and 4.3 ns, respectively. For ArLi+, the theoretical spectrum from both excited states is 119.8 nm, while the experimental one is 124.7 nm. The lifetimes are 4.5 ns for 2 1Σ+ and 23 ns for 1 1Π. © 1991 American Institute of Physics.
  • S NAMBU, K NAKATA, S IWATA
    CHEMICAL PHYSICS, 135(1) 75-83, Jul, 1989  
  • N SATO, S NANBU, S IWATA
    CHEMICAL PHYSICS LETTERS, 146(3-4) 275-279, May, 1988  

Misc.

 5
  • Toshimasa Ishida, Shinkoh Nanbu, Hiroki Nakamura
    INTERNATIONAL REVIEWS IN PHYSICAL CHEMISTRY, 36(2) 229-285, 2017  Peer-reviewedInvited
    It is now confirmed that the Zhu-Nakamura (ZN) theory of nonadiabatic transition is useful to investigate various nonadiabatic chemical dynamics. The theory, being one-dimensional, presents a whole set of analytical formulas that enables us to treat the dynamics efficiently. It is also quite significant that classically forbidden transitions can be dealt with analytically. The theory can be combined with the trajectory surface hopping (TSH) method (ZN-TSH) and is demonstrated to be useful to clarify the dynamics of not only simple tri-atomic reactions but also large chemical systems. The whole set of analytical formulas directly applicable to practical systems is summarised and the applications to polyatomic systems are illustrated. Examples of polyatomic molecules are H2SO4, NH3, indolylmaleimide, cyclohexadiene (CHD), and retinal. The Fortran code for the whole set of ZN formulas is provided in Appendix for the convenience of a reader who is interested in using them. The ZN-TSH method can be combined with the QM/MM method to clarify reaction dynamics in the surrounding environment. This is named as ZN-QM/MM-TSH. The particle-mesh Ewald (PME) method can also be combined with ZN-TSH to clarify reaction dynamics in solutions. This is named as ZN-PME-TSH. Formulations of these methods are presented together with practical applications. Examples treated by ZN-QM/MMTSH are photoisomerization dynamics of retinal chromophore embedded in the protein environment. The differences in the isomerization mechanisms between rhodopsin and isorhodopsin are made clear. The faster and more efficient isomerization of rhodopsin compared to isorhodopsin is nicely reproduced. Examples of reactions in solutions are photoisomerizations of retinal and CHD. The experimentally observed long life time of the excited state of retinal is reproduced and is found to be due to the long-range solvation effect. The solvent dependent branching ratios of CHD: hexatriene (HT) are clarified for the ethanol and hexane solvents by the ZN-PME-TSH method. Both ZN-QM/MM-TSH and ZN-PME-TSH are thus demonstrated to be promising methods to deal with a wide range of nonadiabatic dynamics in large chemical and biological systems.
  • Shinkoh Nanbu, Toshimasa Ishida, Hiroki Nakamura
    CHEMICAL SCIENCE, 1(6) 663-674, 2010  Peer-reviewedInvitedLead authorCorresponding author
    A variety of chemical phenomena are governed by non-adiabatic transitions at conical intersections of potential energy surfaces, if not directly, but indirectly in the midst of the processes. In other words, the non-adiabatic transition makes one of the most significant key mechanisms in chemical dynamics. Since the basic analytical theory is now available to treat the transitions, it is possible to comprehend the dynamics of realistic chemical and biological systems with the effects of transitions taken into account properly. Another important quantum mechanical effect of tunneling can also be taken into account. Furthermore, it becomes feasible to control chemical dynamics by controlling the non-adiabatic transitions at conical intersections, and also to develop new molecular functions by using peculiar properties of non-adiabatic transitions. These may be realized, if we apply appropriately designed laser fields. This perspective review article explains the above mentioned ideas based on the authors' recent activities. The non-adiabatic chemical dynamics is expected to open a new dimension of chemistry.
  • Manabu Nakazono, Ai Jinguji, Kenichiro Saita, Shinkoh Nanbu, Ryoichi Kuwano, Kiyoshi Zaitsu
    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY, 237, Mar, 2009  
  • Koga, N, Matsushita, T, Hashimoto, K, Hada, M, Hosoya, H, Matsuzawa, H, Nagashima, U, Nanbu S, Takano, K, Yamabe, S
    J. Mol. Struct. (THEOCHEM), 720-721 1-666, 2005  Invited
  • Kamisaka Hideyuki, Nanbu Shinkoh, Bian Wensheng, Aoyagi Mutsumi, Tanaka Kiyoshi, Nakamura Hiroki
    Meeting abstracts of the Physical Society of Japan, 57(1) 157-157, Mar 1, 2002  

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