# Mathematical Methods in Quantum Chemistry

### Gero Friesecke

Technische Universität München, München Garching, Germany### Peter Gill

Australian National University, Canberra, Australia

## Abstract

The field of quantum chemistry is concerned with the analysis and simulation of chemical phenomena on the basis of the fundamental equations of quantum mechanics. Since the ‘exact’ electronic Schrödinger equation for a molecule with $N$ electrons is a partial differential equation in 3$N$ dimension, direct discretization of each coordinate direction into $K$ gridpoints yields $K^{3N}$ gridpoints. Thus a single Carbon atom ($N = 6$) on a coarse ten point grid in each direction ($K = 10$) already has a prohibitive $10^{18}$ degrees of freedom. Hence quantum chemical simulations require highly sophisticated model-reduction, approximation, and simulation techniques. The workshop brought together quantum chemists and the emerging and fast growing community of mathematicians working in the area, to assess recent advances and discuss long term prospects regarding the overarching challenges of

(1) developing accurate reduced models at moderate computational cost,

(2) developing more systematic ways to understand and exploit the multiscale nature of quantum chemistry problems.

Topics of the workshop included:

• wave function based electronic structure methods,

• density functional theory, and

• quantum molecular dynamics.

Within these central and well established areas of quantum chemistry, the workshop focused on recent conceptual ideas and (where available) emerging mathematical results.

## Cite this article

Gero Friesecke, Peter Gill, Mathematical Methods in Quantum Chemistry. Oberwolfach Rep. 8 (2011), no. 2, pp. 1769–1843

DOI 10.4171/OWR/2011/32