# LINE ASSIGNMENTS AND GLOBAL ANALYSIS OF THE TUNNELING-ROTATIONAL MICROWAVE ABSORPTION SPECTRUM OF DIMETHYL METHYLPHOSPHONATE

Please use this identifier to cite or link to this item: http://hdl.handle.net/1811/20715

Files Size Format View
2002-WI-08.jpg 340.1Kb JPEG image

 dc.creator Ohashi, N. en_US dc.creator Pyka, J. en_US dc.creator Golubiatnikov, G. Yu. en_US dc.creator Hougen, Jon T. en_US dc.creator Suenram, R. D. en_US dc.creator Lovas, F. J. en_US dc.creator Lesarri, Alberto en_US dc.creator Kawashima, Y. en_US dc.date.accessioned 2006-06-15T20:31:42Z dc.date.available 2006-06-15T20:31:42Z dc.date.issued 2002 en_US dc.identifier 2002-WI-08 en_US dc.identifier.uri http://hdl.handle.net/1811/20715 dc.description Author Institution: Department of Physics, Faculty of Science, Kanazawa University; Faculty of Chemistry, Adam Mickiewicz University; Institute of Applied Physics, Russian Academy of Sciences; Optical Technology Division, National Institute of Standards and Technology; Departamento de Quimica-Fisica, Facultadde Ciencias, Universidad de Valladolid; Department of Applied Chemistry, Kanagawa Institute of Technology en_US dc.description.abstract We have carried out line assignments of about 600 transitions involving levels of all six symmetry species in the $G_{18}$ molecular symmetry group, covering J and K values of $2 \leq J \leq 6$ and $0 \leq |K| \leq 3$. The assignments are based primarily on combination difference loops and on differences in line shape for different symmetry species caused by the small internal rotor splitting patterns of the third, high-barrier methyl top. A global fit to a group-theoretically derived effective rotational Hamiltonian for this ten-dimensional vibrational tunneling problem was carried out, but a least-squares fit to nearly experimental precision for this floppy molecule required 116 parameters. From one point of view, this corresponds to a ratio of about 5 lines per parameter. From another point of view it corresponds to about 23 parameters per symmetry species (where each symmetry species can be considered, for parameter counting purposes, as a separate isolated state of the molecule.) These ratios suggest either that more data should be collected, or that a more efficient tunneling-rotational Hamiltonian should be devised. This question, as well as the physical interpretation of some of the more interesting tunneling splittings will be discussed. en_US dc.format.extent 348306 bytes dc.format.mimetype image/jpeg dc.language.iso English en_US dc.publisher Ohio State University en_US dc.title LINE ASSIGNMENTS AND GLOBAL ANALYSIS OF THE TUNNELING-ROTATIONAL MICROWAVE ABSORPTION SPECTRUM OF DIMETHYL METHYLPHOSPHONATE en_US dc.type article en_US