@article {2623,
	title = {Stretch-bend combination polyads in the (A)over-tilde(1)A(u) state of acetylene, C2H2},
	journal = {Journal of Molecular Spectroscopy},
	volume = {256},
	number = {2},
	year = {2009},
	note = {ISI Document Delivery No.: 478PDTimes Cited: 0Cited Reference Count: 55Steeves, Adam H. Bechtel, Hans A. Merer, Anthony J. Yamakita, Nami Tsuchiya, Soji Field, Robert W.},
	month = {Aug},
	pages = {256-278},
	type = {Article},
	abstract = {Rotational analyses are reported for a number of newly-discovered vibrational levels of the SI-trans; ((A) over tilde (1)A(u)) state of C2H2. These levels are combinations where the Franck-Condon active nu(2){\textquoteright} and nu(3){\textquoteright} vibrational modes are excited together with the low-lying bending vibrations, nu(4){\textquoteright} and nu(6){\textquoteright}. The structures of the bands are complicated by strong a- and b-axis Coriolis coupling, as well as Darling-Dennison resonance for those bands that involve overtones of the bending vibrations. The most interesting result is the strong anharmonicity in the combinations of nu(3){\textquoteright} (trans bend, a(g)) and nu(6){\textquoteright} (in-plane cis bend, b(u)). This anharmonicity presumably represents the approach of the molecule to the trans-cis isomerization barrier, where ab initio results have predicted the transition state to be half-linear, corresponding to simultaneous excitation of nu(3){\textquoteright} and nu(6){\textquoteright}. The anharmonicity also causes difficulty in the least squares fitting of some of the polyads, because the simple model of Coriolis coupling and Darling-Dennison resonance starts to break down. The effective Darling-Dennison parameter, K-4466, is found to increase rapidly with excitation of nu(3){\textquoteright}, while many small centrifugal distortion terms have had to be included in the least squares fits in order to reproduce the rotational structure correctly. Fermi resonances become important where the K-structures of different polyads overlap, as happens with the 2(1)3(1)B(1) and 3(1)B(3) polyads (B = 4 or 6). The aim of this work is to establish the detailed vibrational level structure of the S-1-trans state in order to search for possible S-1-cis ((1)A(2)) levels. This work, along with results from other workers, identifies at least one K sub-level of every single vibrational level expected up to a vibrational energy of 3500 cm(-1). (C) 2009 Elsevier Inc. All rights reserved.},
	keywords = {1AU, AB-INITIO MO, acetylene, Cis-trans isomerization, DISPERSED, DOUBLE-RESONANCE SPECTROSCOPY, FLUORESCENCE, FLUORESCENCE-SPECTRUM, INTRAMOLECULAR VIBRATIONAL REDISTRIBUTION, LASER-INDUCED, PARTIAL DEPERTURBATION, POLYATOMIC-MOLECULES, ROTATION CONSTANTS, STATE, vibration-rotation analysis, X BAND SYSTEM},
	isbn = {0022-2852},
	url = {<Go to ISI>://000268599300013},
	author = {Steeves, A. H. and Bechtel, H. A. and Merer, A. J. and Yamakita, N. and Tsuchiya, S. and Field, R. W.}
}
@article {2260,
	title = {Direct observation of the symmetric stretching modes of (A)over-tilde(1) A(u) acetylene by pulsed supersonic jet laser induced fluorescence},
	journal = {Molecular Physics},
	volume = {106},
	number = {15},
	year = {2008},
	note = {ISI Document Delivery No.: 371LATimes Cited: 1Cited Reference Count: 24Steeves, Adam H. Merer, Anthony J. Bechtel, Hans A. Beck, Annelise R. Field, Robert W.},
	pages = {1867-1877},
	type = {Article},
	abstract = {Rotational analyses are reported for the 2(0)(2) and 1(0)(1) bands of the (A) over tilde (1) A(u) <- (X) over tilde (1) Sigma(+)(g) transition of C2H2 near 45,000 cm(-1) (+2800 cm(-1) relative to T-0) from jet-cooled laser-induced fluorescence spectra. While the 220 band is unperturbed and straightforward to assign, the 1(1) level is strongly perturbed by interactions with the 2(1) B-2 polyad, where upsilon B{\textquoteright} = upsilon(4){\textquoteright} + upsilon(6){\textquoteright}. In order to assign the lines of this band, a population-labelling technique was used, employing an infrared laser to deplete the population in selected ground state rotational levels before probing with the ultraviolet laser. Deperturbation of the 1(1)/2(1) B-2 interaction leads to the value v(1){\textquoteright} = 2880.08 cm(-1) for the fundamental symmetric C-H stretching frequency. Assignments are also reported for the 2 3 and 1 1 2 1 levels, completing all assignments of levels containing excitation in only the totally symmetric vibrational modes up to + 4500 cm(-1). The reassignment of upsilon(1){\textquoteright} implies that some of currently accepted assignments above 47,000 cm(-1) are in error and suggests that the interpretation of some aspects of the near-threshold photodissociation measurements of Mordaunt et al. [J. Chem. Phys. 108, 519 (1998)] may need to be revisited.},
	keywords = {AB-INITIO MO, acetylene, ASSIGNMENT, C2H2, DEPERTURBATION, excited states, PARTIAL, PHOTODISSOCIATION, S-1((1)A(U)) STATE, SPECTROSCOPY, vibration-rotation analysis, VIBRATION-ROTATION CONSTANTS, vibrational spectroscopy, WAVELENGTH BANDS, X BAND SYSTEM},
	isbn = {0026-8976},
	url = {<Go to ISI>://000260831600004},
	author = {Steeves, A. H. and Merer, A. J. and Bechtel, H. A. and Beck, A. R. and Field, R. W.}
}
@article {4107,
	title = {Monte Carlo simulations of solute ordering in nematic liquid crystals: Shape anisotropy and quadrupole-quadrupole interactions as orienting mechanisms},
	journal = {Physical Review E},
	volume = {55},
	number = {4},
	year = {1997},
	note = {ISI Document Delivery No.: WV249Times Cited: 17Cited Reference Count: 51},
	month = {Apr},
	pages = {4321-4337},
	type = {Article},
	abstract = {Monte Carlo computer simulations were used to investigate the effects of shape anisotropy and electrostatic interactions as mechanisms for orientational ordering of solutes in nematic liquid crystals. The simulation results were analyzed in terms of two theories of solute ordering which derive mean-field orientational potentials from the intermolecular pair potential. In the calculations, solute and solvent molecular shapes were approximated by hard ellipsoids. Most simulations also incorporated the interaction between point quadrupole moments placed at the centers of the ellipsoids. In the hard-core systems, orientational order parameters and distribution functions were calculated for a collection of different solutes under a variety of conditions. A theory due to Terzis and Photinos [Mol. Phys. 83, 847 (1994)] was found to underestimate the effect of shape anisotropy on orientational ordering drastically. The introduction of an effective solvent packing fraction was unable to improve the predictive power of the theory significantly. The quadrupolar systems were used to investigate a mean-field model for solute ordering which considers an interaction between the solute molecular quadrupole moment with an average electric-field gradient. The simulations indicate that the electric-field gradient sampled by the solute is highly dependent on the properties of the solute, contrary to some experimental evidence. Further, the effects of the intermolecular quadrupolar interactions on orientational ordering and the electric-field gradient were analyzed using a mean-field potential derived here and based on the theory due to Emsley, Palke, and Shilstone [Liq. Cryst. 9, 649 (1991)]. This model was found to provide a qualitatively correct but quantitatively imprecise prediction of orientational ordering.},
	keywords = {acetylene, COMPUTER-SIMULATION, ELECTRIC-DIPOLE INTERACTIONS, HARD ELLIPSOIDS, MEAN TORQUE, MOLECULAR-HYDROGEN, NMR, orientational order, POTENTIALS, SOLVENTS},
	isbn = {1063-651X},
	url = {<Go to ISI>://A1997WV24900067},
	author = {Polson, J. M. and Burnell, E. E.}
}
@article {3430,
	title = {A NOVEL SURFACE-STRUCTURE - RH(111)-(ROOT-7X-ROOT-7)R19.1-DEGREES-P},
	journal = {Journal of the American Chemical Society},
	volume = {117},
	number = {49},
	year = {1995},
	note = {ISI Document Delivery No.: TK382Times Cited: 7Cited Reference Count: 26},
	month = {Dec},
	pages = {12344-12345},
	type = {Note},
	keywords = {acetylene, chemisorption, CYCLOTRIMERIZATION, ENERGY-ELECTRON-DIFFRACTION, HETEROCYCLIZATION SITES, INTERMEDIATE, MOLECULAR PATHWAYS, palladium, SUBSTRATE, SULFIDED PD(111) SURFACE},
	isbn = {0002-7863},
	url = {<Go to ISI>://A1995TK38200041},
	author = {Liu, W. and Wong, K. C. and Mitchell, K. A. R.}
}
