Colloquium
Department of Physics, NCU
An Effective Hamiltonian Approach to Calculating Rotational Energy Levels of CH5+, using Ideas from Atomic Spectroscopy
Speaker
Dr. Jon T. Hougen
Sensor Science Division, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
Date 2017.05.23(Tue)
Time 14:00
Place S4-625
CH5+ is a molecular ion with no fixed equilibrium structure, which means that the five H atoms orbit around the C atom much like electrons orbit around an atomic nucleus. This situation is very different from that in an ordinary molecule like CH4, where the H atoms are highly localized near the corners of a tetrahedron and only make short vibrational displacements from their equilibrium positions. Because of the large-amplitude motions of the H atoms in CH5+, no existing vibration-rotation Hamiltonian is capable of describing its energy levels. Thus, not even one line has been assigned in the three high-resolution infrared spectra that exist for this molecule (one of which is already 30 years old). In this talk a general introduction to the CH5+ problem, as well as details associated with the topics in the title will be presented. (鄭王曜注：從美國國家實驗室(NIST)來的Dr. Hougen是物理化學的專家, 知道量子力學的同學，很適合來聽，例如，有個Hamiltonian就是以他的名字命名(HBJ)。他是世界上許多研究所的advisor (含中研院原分所)。他善於深入淺出的演講，同學們就算聽不太懂，學到他的演講技術都值得。他的願望是協助全世界做光譜的年輕人，甚至為了這個目的去學五國語言。因此同學們可儘量發問，必有收穫)