The Simplest Molecule.

Title

The Simplest Molecule.

Speaker

Dr. Iain R McNab (formerly of University of Newcastle upon Tyne, UK)

Host

Prof. Kai Huang (GTIIT, Chemistry)

Time and Location

Dec. 29 2022, Thursday, 11:00am-12:00pm(China Time), Online

Zoom: 94609938903

https://gtiit.zoom.us/j/94609938903

Abstract

The simplest molecule is H₂⁺ made from just two protons and one electron. It is the molecular analogue of atomic hydrogen – it is a testcase used in all the most accurate theoretical work on molecules. It is the only molecule for which the Schrödinger equation can be solved exactly (within the Born Oppenheimer approximation). Despite its theoretical importance, it is hard to make measurements on H₂⁺ because it is highly reactive. I will briefly discuss how the ionization of hydrogen molecules drives interstellar chemistry. I will discuss measurements in H₂⁺ close to the dissociation limit using a modified mass spectrometer, and measurements in H₂⁺ close to the ground state using ion traps. Experiments and theory agree to better than one part in 10^8, this level of accuracy is approaching that needed to use these measurements as new ways of defining fundamental physical constants.