@article {630,
	title = {The Renner-Teller effect and Sears resonances in the ground state of the GeCH and GeCD free radicals},
	journal = {Journal of Chemical Physics},
	volume = {119},
	number = {19},
	year = {2003},
	note = {ISI Document Delivery No.: 738EFTimes Cited: 8Cited Reference Count: 15},
	month = {Nov},
	pages = {10115-10124},
	type = {Article},
	abstract = {The vibrational energy levels of the jet-cooled GeCH and GeCD radicals have been studied by a combination of laser-induced fluorescence and wavelength-resolved emission techniques. The radicals were produced in a pulsed electric discharge free jet expansion using methyltrichlorogermane and tetramethylgermane-d(12) precursors. A re-examination of the weaker hot bands in the LIF spectrum has provided a more complete vibrational analysis of the upper state energy levels. The single vibronic level emission spectra obtained by pumping several bands of each isotopomer were analyzed to provide information on the low-lying ground state vibronic energy levels up to 3000 cm(-1) above the zero-point level. Strong interactions occur in these molecules between vibronic levels with the same value of P, but differing by one unit of v(2); such interactions were first described for NCS by Northrup and Sears [Mol. Phys. 71, 45 (1990)] and are conveniently called "Sears resonances." The spectra of GeCH were further complicated by Fermi resonances between the bending and Ge-C stretching levels. Despite these difficulties, it proved possible to analyze the data using a standard Renner-Teller model with the addition of Sears resonance coupling terms. The validity of the fitted parameters was tested using the isotope relations. The Sears resonance parameters for GeCH are much larger than those of NCS, a result of the much stronger vibronic coupling in the germanium methylidynes. (C) 2003 American Institute of Physics.},
	keywords = {ELECTRONIC-SPECTRUM, GERMANIUM METHYLIDYNE, ORBITAL ANGULAR-MOMENTUM, SILICON METHYLIDYNE SICH, SPECTROSCOPY},
	isbn = {0021-9606},
	url = {<Go to ISI>://000186273200016},
	author = {He, S. G. and Li, H. Y. and Smith, T. C. and Clouthier, D. J. and Merer, A. J.}
}
@article {4458,
	title = {Electronic spectra of YOH and YOD in the visible region: Strong vibronic coupling between the (B)over-tilde(1)II and (C)over-tilde(1)Sigma(+) states},
	journal = {Journal of Molecular Spectroscopy},
	volume = {196},
	number = {1},
	year = {1999},
	note = {ISI Document Delivery No.: 208RCTimes Cited: 7Cited Reference Count: 41},
	month = {Jul},
	pages = {45-69},
	type = {Article},
	abstract = {Laser excitation spectra of yttrium monohydroxide, YOH, have been recorded in the 500-625 nm wavelength region. Rotational analysis of bands of YOH and YOD has shown that the ground state is (X) over tilde(1)Sigma(+), with the structure r(0)(Y-O) = 1.948(6) Angstrom, r(0)(O-H) = 0.920(6) Angstrom; the bending frequency (nu(2), pi) is 313.73 cm(-1) (237.43 cm(-1) in YOD) and the Y-O stretching frequency (nu(3), sigma(+)) is 673.83 cm(-1) (655.34 cm(-1)). Two excited electronic states have been identified; they are assigned as (B) over tilde(1)Pi (16 449 cm(-1)) and (C) over bar(1)Sigma(+) (18 509 cm(-1)). Unusually strong vibronic coupling through the bending vibration occurs between these two states, which causes their vibrational structures to be highly irregular; assignments have only been possible following extensive wavelength-resolved fluorescence experiments. The vibronic coupling raises the bending frequency of the (C) over tilde(1)Sigma(+) state to 457 cm(-1) and reduces that of the lower Born-Oppenheimer component of the (B) over tilde(1)Pi state (which has A{\textquoteright} symmetry in the C, point group) to the extent that the molecule becomes nonlinear, with a potential barrier at the linear configuration of about 120 cm(-1). The presence of the potential barrier is clearly demonstrated by the level structure of YOD, where the Sigma(+) vibronic component of the 010 vibrational level (linear molecule notation) lies 1.4 cm(-1) below the 000 level. The upper Born-Oppenheimer component, which has A " symmetry, is unaffected; its bending frequency is similar to that of the ground state. Perturbations occur in both the (B) over tilde(1)Pi and (C) over tilde(1)Sigma(+) states; some of these represent local interactions between the two of them, but others are caused by higher vibrational levels of lower-lying "dark" electronic states. Over 40 ground state vibrational levels have been identified for both YOH and YOD from the wavelength-resolved fluorescence spectra. (C) 1999 Academic Press.},
	keywords = {15-K, laser spectroscopy, METHYLIDYNE, ORBITAL ANGULAR-MOMENTUM, RESONANCE, SYSTEM, TRANSITION, TRIATOMIC-MOLECULES, VANADIUM, WATER},
	isbn = {0022-2852},
	url = {<Go to ISI>://000081004300006},
	author = {Adam, A. G. and Athanassenas, K. and Gillett, D. A. and Kingston, C. T. and Merer, A. J. and Peers, J. R. D. and Rixon, S. J.}
}
