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    COLLOQUIUM OF THE LABORATORY FOR COMPUTER DESIGN OF MATERIALS
        Institute for Computational Sciences and Informatics
	                      CSI 898-Sec 001  
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          Spectroscopy, Thermochemistry, and Computational Chemistry:
                    The Hydroxymethyl (CH2OH) Radical

                         Russell D. Johnson III
Computational Chemistry Group, Physical and Chemical Properties Division
    National Institute of Standards and Technology, Gaithersburg, MD 

CH2OH (hydroxymethyl) and its isomer, CH3O (methoxy), play important roles
in the combustion of hydrocarbon fuels, atmospheric pollution chemistry,
surface science, and interstellar chemistry. Despite a plethora of research
on hydroxymethyl the literature reveals that several fundamental properties
lie in contention. In particular, the heats of formation for the CH2OH
radical, derived from kinetic equilibria of neutral reactants are 
consistently 5-11 kJ mol-1 greater than those obtained from ion appearance 
energy data. This difference in enthalpy resulted from an incorrect entropy.

In order to understand this difference, we undertook a two-pronged attack:
1) Obtain and evaluate spectroscopic data for low frequency vibrations, and
2) Determine the low frequency vibrations through ab initio computations.
The problems arose because the CH2OH radical is floppy and has coupled
vibrations. This talk will discuss the spectroscopy and calculations needed
for understanding this non-rigid radical.

	               Monday , February 8 1999
                                 4:30 pm
                        Room 206, Science & Tech. I

Refreshments will be served.
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(http://www.csi.gmu.edu/lcdm/seminar/schedule.html)