Irmgard Frank

Leibniz Universität Hannover, Germany

Title: How chemistry leads to deterministic quantum mechanics

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Biography

Irmgard Frank studied chemistry at the LMU Munich (1988 – 1993). She went to the University of Bonn where she completed her PhD thesis in 1995. She became a postdoc at the Max-Planck institute for solid state science in Stuttgart where she developed the restricted-open shell Kohn-Sham method (ROKS) for the simulation of photoreactions. She went back to Munich and completed her Habilitation in 2004. Her work focused on the ab-initio simulation of chemical reactions. In 2008 she was appointed associate professor at the University of Hannover. More recently, she develops deterministic quantum mechanics.

Abstract

The simulation of chemical reactions is the holy grail of quantum chemistry. In the end one wants to see movies that show the nuclear motion. In addition, it is nice to see the motion of the electronic cloud accompanying and explaining this nuclear motion. Of course, we follow the Rutherford picture of very small nuclei (femtometer scale) within an atom (picometer scale). We lose no accuracy if we describe the nuclei as classical point charges. As it turns out, we have indeed no alternative to this picture, if we describe the electronic cloud with the Schrödinger equation. Consistently, we can move the nuclei with classical Newton dynamics. This approach is already implemented as ab-initio molecular dynamics – unfortunately: we arrive at nothing new, trial and error already led there;  fortunately: we can immediately test this approach. It turns out that this deterministic version of quantum mechanics describes reactions, including photo reactions, just perfectly. A vibrational zero-point energy is not needed, the electronic zero-point energy is more than enough.  From comparison to experiment at normal energies, we get no hint how to improve this theory of classical nuclear motion. It works fine at normal energies. Classical nuclear motion has philosophical implications: Schrödingers cat dies deterministicly. Note that our approach is not identical with Bohm mechanics. Instead of a guidance equation we simply have Newtons equation.