Dear Friends, On Thursday, October 25, there will be an ITAMP topical discussion. NOTE UNUSUAL PLACE! M-240 (2d floor) @ Concord ave. 160 Time: 12:00-1:30 As always pizza will be served. The building is in front of the CfA on the Concord ave: http://goo.gl/HE4hJ Speaker: Josh Baraban (MIT) Title: Spectroscopic Characterization of Transition States Abstract: Conventional wisdom has always held that transition states are impossible to observe and characterize experimentally. With the exceptions of ultrafast spectroscopy and ab initio electronic structure calculations, direct information about these critical points on potential energy surfaces has therefore been very limited. We have recently demonstrated for the first time that it is possible to characterize a transition state by high resolution spectroscopic methods, using the cis-trans isomerization in the well-known A state of acetylene as a prototypical system. New spectroscopic patterns related to the properties of transition states will be discussed, in addition to the experimental and theoretical techniques employed to decipher the complex spectra and dynamics of isomerizing molecules. Looking forward to seeing you there, Misha Lemeshko -- Dr. Mikhail Lemeshko Institute for Theoretical Atomic, Molecular, and Optical Physics (ITAMP) Harvard-Smithsonian Center for Astrophysics MS-14 60 Garden St. Cambridge, MA 02138 U.S.A. mlemeshko(a)cfa.harvard.edu http://sites.google.com/site/mishalemeshko/ Tel. +1 (617) 496-7610 Fax +1 (617) 496-7668