Electronic structure of Rydberg states of triatomic hydrogen, neon hydride, hydrogen fluoride (H2F), H3O, NH4 and CH5 molecules

Raynor, Susanne; Herschbach, D. R.

doi:10.1021/j100215a020

Cited by 78 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, bound states of the neutral radicals FH2, OH3, and NH4, referred to as Rydberg molecules, are known to exist from numerous experimental and theoretical studies (see, e.g. , Raynor and Herschbach [45] and Kaspar, Smith, and McMaster [46]). By analogy we may conclude that those K-shell excitations described as X 1s Rydberg transitions are stable, or at least metastable, with respect to fragmentation.…”

Section: General Discussion and Conclusionmentioning

confidence: 99%

K-shell excitation of the water, ammonia, and methane molecules using high-resolution photoabsorption spectroscopy

et al. 1993

View full text Add to dashboard Cite

The K-shell excitation spectra of the hydrides water, ammonia, and methane have been measured in photoabsorption experiments using synchrotron radiation in combination with a high-resolution monochromator. For the case of methane, in particular, a wealth of spectral detail is observed which was not accessible in previous studies. The measured excitation energies and relative intensities compare well with values calculated using a complete second-order approximation for the polarization propagator. In order to determine the extent of admixing of valence excitations (i.e., transitions into virtual 0 orbitals) to the Rydberg manifolds, the X-H bond lengths have been varied in the calculations. In the case of H20, the two lowest-energy bands are due to the 0 1s-4a&/3s and 0 1s-2b2/3p transitions and have strong valence character; their width indicates that both excitations are dissociative. The NH3 and ND3 spectra are also broad which is not only due to possible dissociation but also to unresolved vibrational fine structure (v2 mode) and a Jahn-Teller instability. Valence character is concentrated in the lowest excited state in the Rydberg ns manifold, but is distributed more uniformly over the np(e) manifold. The weak dipole-forbidden C 1s -3s ( a & ) transition in CH4 and CD4 is accompanied by vibrational structure due to the v4 mode, indicating that it derives its intensity from vibronic coupling with the C 1s-3p(t2) transition. The structure on the latter band is extremely complicated due to Jahn-Teller coupling and cannot be assigned at present, as is the case for the Rydberg transitions at higher energies. The higher np Rydberg excitations contain considerable valence character. PACS number(s): 33.20.Rm 35.20. -i I. INTRQDUCTIDNE-shell excitation of the CH4, NH3, and H20 molecules has been studied in the past using both electronenergy-loss spectroscopy (EELS) [1 -4] and x-ray absorption spectroscopy [5 -9). Although the spectral resolution obtained with the latter technique has generally been rather modest and could not match that of EELS, recent advances in grazing-incidence monochromator design [10 -14] have resulted in a dramatic improvement of resolution with the "optical" approach. This has been shown in a number of high-resolution K-shell excitation spectra of small molecules reported recently (e.g. , ). In the present paper we describe measurements of the photoabsorption spectrum of gas phase H20, NH3, and CH4 in the near-E-edge region at a resolution sufficiently high to reveal directly the spectral line shape. To substantiate the assignments we have also calculated excitation energies and oscillator strengths using a polarization propagator method [20].In the virtual orbital spectrum of these hydrides and other saturated molecules one expects antibonding valence-type (cr ) orbitals which are the counterparts of the occupied bonding X-H orbitals. An important question is to what extent this antibonding valence character appears in the excitation spectrum. In most of the earlier E-shell studies on the h...

show abstract

Section: General Discussion and Conclusionmentioning

confidence: 99%

K-shell excitation of the water, ammonia, and methane molecules using high-resolution photoabsorption spectroscopy

et al. 1993

View full text Add to dashboard Cite

show abstract

“…It has stimulated a number of theoretical (see, for example, Refs. [4][5][6]) and experimental (see, for example, Refs. [7][8][9]) investigations dealing with the excited electronic states of this molecule.…”

Section: Susanta Mahapatra and Horst Köppelmentioning

confidence: 99%

Quantum Mechanical Study of Optical Emission Spectra of Rydberg-ExcitedH3and Its Isotopomers

Mahapatra

Köppel

1998

Phys. Rev. Lett.

View full text Add to dashboard Cite

Optical emission spectra of Rydberg-excited H 3 , D 3 , H 2 D, and D 2 H, in the range 200 -400 nm, are investigated theoretically and compared with the experimental findings of Bruckmeier et al. [Phys. Rev. Lett. 72, 2550(1994]. The time-dependent wave packet method combined with the vibronic coupling theory for (E 3 e) Jahn-Teller systems is utilized in order to calculate the corresponding Franck-Condon emission profiles from the upper n 3 electronic state to the degenerate ͑2p͒1E 0 ground electronic manifold of those species. We obtain bimodal spectra with two maxima 9600 cm 21 apart in good agreement with the experimental result. [S0031-9007(98)07321-9]

show abstract

“…In our calculations on H,O, we have adopted the C,, pyramidal geometry predicted by Raynor and Herschbach [14] with the procedure we men-tion in the Introduction, in which the bond lengths are 1.824 bohrs and the bond angle is 116". This geometry is in good agreement with that of an earlier calculation by Diercksen et al [341 and with the NMR results obtained by Symons [35].…”

Section: Resultsmentioning

confidence: 99%

“…The QDO formalism is free from these problems and it has even appeared to be quite helpful in solving important controversies in assigning experimentally found spectral bands in NH,, [22]. Additionally, reference to discrepancy between some of their FSSO calculated spectral data and the experimental measurements for H, and NH, is made by Raynor and Herschbach [14]. These facts do not help to support, in our view, a complete reliability of the FSSO results for all of the transitions reported [14].…”

Section: Resultsmentioning

confidence: 99%

Electronic transitions in the Rydberg radical H3O

Martı́n

Campo

Lavín

1995

Int. J. Quantum Chem.

View full text Add to dashboard Cite

show abstract

Electronic structure of Rydberg states of triatomic hydrogen, neon hydride, hydrogen fluoride (H2F), H3O, NH4 and CH5 molecules

Cited by 78 publications

References 0 publications

K-shell excitation of the water, ammonia, and methane molecules using high-resolution photoabsorption spectroscopy

K-shell excitation of the water, ammonia, and methane molecules using high-resolution photoabsorption spectroscopy

Quantum Mechanical Study of Optical Emission Spectra of Rydberg-ExcitedH3and Its Isotopomers

Electronic transitions in the Rydberg radical H3O

Contact Info

Product

Resources

About