PROJECTS

Analysis and reduction of the node location error in electron structure quantum Monte Carlo methods

PRINCIPAL INVESTIGATOR

Prof. Dr. Arne Lüchow Rheinisch-Westfälische Technische Hochschule Aachen Institut für Physikalische Chemie Landoltweg 2 52056 Aachen Germany 0241/8094748 0241/8092748 luechow@pc.rwth-aachen.de www: Homepage

PROJECT RESEARCH ASSISTANT

ABSTRACT

The diffusion quantum Monte Carlo (DMC) method allows the accurate calculation of stabilization and reaction energies for molecules or molecular aggregates from first principles without empirical parameters. This allows the chemist to investigate properties of compounds prior to the actual synthesis, and to support the understanding of reaction path ways of complicated reactions. The DMC method provides a recent alternative to established methods with unique features such as the excellent adaptability to the newest generation of high-performance parallel computers built from clusters of inexpensive standard PCs. The low increase of computational cost with the systemsize allows accurate calculations of systems with hundreds of electrons. In this project we aim at improving the reliability and accuracy of DMC by investigating the only approximation which results in the node error. In the previous grant period we have developed tools for analysis and reduction of this error and for the next grant period we propose to exploit and extent these methods by adapting wave functions used specifically to DMC rather than employing functions taken from other methods. We hope to devise an improved DMC method with higher accuracy that is still applicable to molecules or molecular aggregates with hundreds of electrons.