Vibronic structure of the emission spectra from single vibronic levels of the S1 manifold in naphthalene: Theoretical simulation

The vibrational and rotational structure of the electronic transitions of open-shell cations of linear polyatomics has been studied by three complementary techniques. In one, the emission spectra of ions of unstable species, XCP + and XBS + , with X = H, D and F, are obtained by electron-impact excitation on effusive and supersonic free jets. The vibronic structure of their A1 2£ + —> X2IIi band systems could be analysed. The changes and distinct features of the rotational profiles at low rotational temperatures in the emission spectra of diacetylene cation have been used to establish the absolute numbering in the rotational analysis of the A2Hu-X 2Hg transition. The second approach is based on the measurement of the laser excitation spectra of ions and has been used to confirm the vibrational assignment of complex emission spectra, such as the B2H -» X2IT transition of C1CN+, and to resolve the rotational structure in the A2H| <— X2Hz transitions of the haloacetylene cations XCCH+, X — Cl, Br, I. The most recent development is the demonstration that the stimulated emission pumping approach can be used to probe the electronic structure of ions in a flow system.

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INTRAMOLECULAR ENERGY BAND DISPERSION IN ORIENTED THIN FILM OF n-CF3(CF2)22CF3 STUDIED BY ANGLE-RESOLVED UPS AND THEORETICAL SIMULATION

Surface Review and Letters ◽

10.1142/s0218625x02002397 ◽

2002 ◽

Vol 09 (01) ◽

pp. 407-412 ◽

Cited By ~ 8

Author(s):

DAISUKE YOSHIMURA ◽

KAZUHIKO SEKI ◽

TAKAYUKI MIYAMAE ◽

HISAO ISHII ◽

SHINJI HASEGAWA ◽

...

Keyword(s):

Energy Band ◽

Emission Spectra ◽

Photoemission Spectroscopy ◽

Surface Films ◽

Theoretical Simulation ◽

Angle Resolved Photoemission Spectroscopy ◽

Band Dispersion ◽

Chain Axis ◽

Theoretical Simulations ◽

Long Chain

Electronic structure of perfluorotetracosane [n- CF 3 ( CF 2)22 CF 3; PFT], which is an oligomer of poly(tetrafluoroethylene) (PTFE), was investigated by angle-resolved photoemission spectroscopy (ARUPS) with synchrotron radiation. Theoretical simulations of ARUPS spectra were also performed by the independent atomic center (IAC) approximation combined with ab initio molecular orbital (MO) calculations. Measured normal-emission spectra for end-on oriented (the long-chain axis of PFT is perpendicular to the surface) films showed an incident photon energy dependence due to the intramolecular energy band dispersion. The energy band structure along the long-chain direction of PFT obtained from measured and calculated spectra is also discussed.

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ChemInform Abstract: The Vibronic Structure in the Emission Spectra of Some Thienylpyridine Complexes

ChemInform ◽

10.1002/chin.199739319 ◽

2010 ◽

Vol 28 (39) ◽

pp. no-no

Author(s):

A. C. STUECKL

Keyword(s):

Emission Spectra ◽

Vibronic Structure

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Efficient Semiclassical Dynamics for Vibronic Spectroscopy beyond Harmonic, Condon, and Zero-Temperature Approximations

CHIMIA International Journal for Chemistry ◽

10.2533/chimia.2021.261 ◽

2021 ◽

Vol 75 (4) ◽

pp. 261-266

Author(s):

Tomislav Begušić ◽

Jirí Vaníček

Keyword(s):

Gaussian Approximation ◽

Emission Spectra ◽

Zero Temperature ◽

Theoretical Simulation ◽

Molecular Systems ◽

Atomic Nuclei ◽

Thermo Field Dynamics ◽

Semiclassical Dynamics ◽

Recent Developments ◽

Treat All

Understanding light-induced processes in biological and human-made molecular systems is one of the main goals of physical chemistry. It has been known for years that the photoinduced dynamics of atomic nuclei can be studied by looking at the vibrational substructure of electronic absorption and emission spectra. However, theoretical simulation is needed to understand how dynamics translates into the spectral features. Here, we review several recent developments in the computation of vibrationally resolved electronic spectra (sometimes simply called 'vibronic' spectra). We present a theoretical approach for computing such spectra beyond the commonly used zero-temperature, Condon, and harmonic approximations. More specifically, we show how the on-the-fly ab initio thawed Gaussian approximation, which partially includes anharmonicity effects, can be combined with the thermo-field dynamics to treat non-zero temperature and with the Herzberg-Teller correction to include non-Condon effects. The combined method, which can treat all three effects, is applied to compute the S1 ← S0 and S2 ← S0 absorption spectra of azulene.

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Nano-probe x-ray analysis and high-resolution imaging on planar defects in high-pressure synthesized infinite-layer superconductor

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171377 ◽

1994 ◽

Vol 52 ◽

pp. 728-729

Author(s):

Y. Y. Wang ◽

H. Zhang ◽

V. P. Dravid ◽

H. Zhang ◽

L. D. Marks ◽

...

Keyword(s):

High Pressure ◽

High Resolution ◽

Atomic Structure ◽

Emission Spectra ◽

High Resolution Electron Microscopy ◽

Planar Defects ◽

X Ray ◽

Infinite Layer ◽

Resolution Electron ◽

Resolution Imaging

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.

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