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Masataka Mizushima

Bio: Masataka Mizushima is an academic researcher. The author has contributed to research in topics: Hyperfine structure & Stark effect. The author has an hindex of 8, co-authored 13 publications receiving 273 citations.

Papers
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TL;DR: In this article, it was shown that pure rotational absorption in the molecules belonging to the point group D2d ≡ Vd is possible if the molecule is in the excited, preferably lowest, doubly degenerate vibrational state.
Abstract: It is shown that pure rotational absorption in the molecules belonging to the point group D2d ≡ Vd is possible if the molecule is in the excited, preferably lowest, doubly degenerate vibrational state. The approximate positions of these microwave absorption lines, as calculated from the B value obtained from the infrared data, are given in the case of allene. It is also shown that the pure rotational absorption is possible in the molecules belonging to the point group Td if they are in the excited triply degenerate (F2) vibrational states. The matrix element of dipole moment corresponding to our transition is about the same as that of the overtone vibrational bands, in both cases.

92 citations

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TL;DR: In this paper, the transition probabilities and selection rules for lower triplet-singlet transitions of benzene were derived group-theoretically, using the LCAO one-electron approximation.
Abstract: Transition probabilities and selection rules are calculated for the lower triplet‐singlet transitions of benzene. The relativistic spin‐orbit coupling term combines the triplet state with an intermediate singlet state, and then dipole transition to the ground state occurs. The selection rules are deduced group‐theoretically, and the transition probabilities are calculated using the LCAO one‐electron approximation. The effect of vibration is discussed. The theoretical results obtained agree with Shull's and McClure's experimental results.

89 citations

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TL;DR: In this paper, the Stark effect of asymmetric rotators, including the effect of hyperfine structure, for weak and stronger field cases, was calculated, including linear rotators.
Abstract: The Stark effect of asymmetric rotator is calculated, including the effect of hyperfine structure, for weak and stronger field cases. The result includes the Stark effect of symmetric rotator and linear rotator as special cases.

20 citations

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TL;DR: In this paper, the ESR spectrum of gaseous NO2 has been studied experimentally over the pressure range 0.05-10 torr at X band for a range of polarizing magnetic field 1.5-8 kG.
Abstract: The ESR spectrum of gaseous NO2 has been studied experimentally over the pressure range 0.05–10 torr at X band for a range of polarizing magnetic field 1.5–8 kG. The spectra are interpreted by a theory which includes the effects of anisotropic electronic and molecular magnetism, intermediate coupling of angular momenta, and centrifugal distortion. Well isolated spectral lines at high magnetic field have been employed to give quantitative information on the electronic g tensor.

13 citations

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TL;DR: In this article, the effect of nuclear spin on the statistical weight of each rovibrational levels and the transition probability between them is calculated for allene-type molecules with respect to the rotational spectra of allene molecules.
Abstract: The possibility of observing the rotational spectra of allene‐type molecules was suggested by the present author and Venkateswarlu. In this paper the effect of nuclear spin on the statistical weight of each rovibrational levels and the transition probability between them are calculated.

12 citations


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TL;DR: Theorie des effets de couplage vibronique multimodes is described in this paper, where couplages mettant en jeu des modes and des etats degeneres.
Abstract: Mise au point. Theorie des effets de couplage vibronique multimodes. Probleme a 2 etats. Couplage vibronique mettant en jeu des modes et des etats degeneres. Effets du couplage vibronique multimodes en spectroscopie. Comportement statistique des niveaux d'energie vibroniques. Intersections coniques et evolution temporelle de la fluorescence

1,424 citations

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TL;DR: In this paper, a previously given theory of the electronic spectra and structure of complex unsaturated molecules is further elucidated by listing specific formulas for the charge density, bond order, transition moment, and configuration interaction matrix elements.
Abstract: A previously given theory of the electronic spectra and structure of complex unsaturated molecules is further elucidated by listing specific formulas for the charge density, bond order, transition moment, and configuration interaction matrix elements.The theory is then applied to give a number of simple rules for alternant hydrocarbons. These refer to the energies of the singly excited states and the effects of configuration interaction, the degeneracy between certain singlet and triplet states, the prohibition of certain electronic transitions which would be allowed from a group theoretical point of view, and the charge density distribution of the ground and singly excited states. A mechanism is proposed to explain some of the anomalously rapid singlet‐triplet radiationless transitions which are observed in connection with studies of the lower triplet states of complex molecules.Quantitative application of the theory is made to the spectra of the polyacenes, benzene through pentacene, and to the bond ord...

964 citations

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TL;DR: In this paper, the long principal magnetic axis in the plane of the phenanthrene molecule was taken as the x axis, the short axis was taken to be the y axis, and the normal to the plane was taken by the z axis.
Abstract: Electron paramagnetic resonance absorption in phenanthrene in its lowest photoexcited triplet state has been investigated at the boiling point of N2. The measurements have been made on phenanthrene molecules, oriented in diphenyl host crystals, at the frequency ∼2.3×1010 cycle sec—1 and also at lower frequencies at almost zero field (76 to 3 G). Taking the long principal magnetic axis in the plane of the phenanthrene molecule to be the x axis, the short axis in the plane to be the y axis, and the normal to the plane to be the z axis, the results have been described by the spin Hamiltonian, H=|β|H·g·S+S·T·S, where S=1,Tzz/hc≡D/hc=±0.100430 cm−1, σ{D/hc}=0.000010 cm−1,−Tyy/hc=Txx/hc≡E/hc=∓0.046576 cm−1, σ{E/hc}=0.000009 cm−1,gzz=+2.00209, σ{gzz}=0.00005,gyy=+2.00279, σ{gyy}=0.00005,gxx=+2.0041., A preliminary investigation of the hyperfine structure has been made. These results have been compared with published calculations.

280 citations

Journal ArticleDOI
TL;DR: In this article, the Davydov splitting of the first triplet excitons in crystalline naphthalene, anthracene, and biphenyl was studied.
Abstract: In the present paper we consider the band structure and the Davydov splitting of the first triplet exciton states in crystalline naphthalene, anthracene, and biphenyl. It is found that: (a) An important contribution to the triplet exciton bandwidth arises from intermolecular exchange interaction. These interactions are calculated in the molecular orbital π‐electron approximation. (b) Excitation exchange effects due to spin—orbit coupling are negligible. (c) Nonorthogonality corrections, considered within the framework of the symmetric orthogonalization procedure, have been found to be small. (d) Crystal‐field mixing of triplet states arising from π→π* excitations has no effect on the triplet bands. (e) An important contribution to the triplet exciton bandwidth may arise from configuration interaction with charge‐transfer states.The dynamics of triplet excitons in aromatic crystals was studied in the two limiting cases of strong and weak scattering. The band model, with the constant mean‐free‐path approxim...

237 citations