@article {2933,
	title = {THE MICROWAVE-SPECTRUM, STRUCTURE, AND HARMONIC FORCE-FIELD OF THE VANDERWAALS TRIMER AR2-OCS},
	journal = {Journal of Chemical Physics},
	volume = {98},
	number = {4},
	year = {1993},
	note = {ISI Document Delivery No.: KP938Times Cited: 25Cited Reference Count: 28},
	month = {Feb},
	pages = {2735-2741},
	type = {Article},
	abstract = {The microwave rotational spectra of the van der Waals trimers Ar2-OCS, (Ar2-OCS)-S-34, and (Ar2-OCS)-18 have been observed between 7.0 and 18.0 GHz using pulsed molecular beam microwave Fourier transform (MWFT) spectroscopy. Sixty-five transitions, both a and c type, have been assigned for Ar2-OCS, as well as 37 transitions and 19 transitions for (Ar2-OCS)-S-34 and (Ar2-COS)-O-18 respectively. The rotational constants and quartic centrifugal distortion constants have been determined. The trimer has been found to be a distorted tetrahedrally shaped highly asymmetric top (K= approximately 0.377) with the OCS subunit lying in the C(s) symmetry plane. An effective ground state structure has been determined. The Ar-Ar distance and the two {\textquoteright}{\textquoteright}Ar-center of mass of OCS{\textquoteright}{\textquoteright} distances are slightly longer than those in the corresponding dimers Ar2 and Ar-OCS, respectively. A harmonic force field analysis has been performed on the basis of the centrifugal distortion constants, to predict the van der Waals force constants and the corresponding vibrational frequencies. The Ar-Ar stretch force constant of the trimer is 0.008 42 mdyn angstrom-1 which compares favorably with 0.0078 mdyn angstrom-1 reported for the free dimer Ar2. A comparison of the geometry and spectroscopic properties of Ar2-OCS with those of Ar2 and of the Ar2-HX (X = F, Cl, CN) trimers is given.},
	keywords = {AR-HCN, AR2HCL, ARHCL, CLUSTER, CONSTANTS, laser spectroscopy, ROTATIONAL SPECTRA},
	isbn = {0021-9606},
	url = {<Go to ISI>://A1993KP93800024},
	author = {Xu, Y. J. and Gerry, M. C. L. and Connelly, J. P. and Howard, B. J.}
}
