Implementation of the multicomponent density functional theory to include quantum effects in nuclear dynamics simulations

• Grant number: 06/04919-5
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: May 01, 2007
• End date: January 31, 2008
• Field of knowledge: Physical Sciences and Mathematics - Physics - Condensed Matter Physics
• Principal Investigator: Antonio José Roque da Silva
• Grantee: Márcio Teixeira do Nascimento Varella
• Host Institution: Instituto de Física (IF). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

We propose the implementation of a Multicomponent Density Functional Theory (MCDFT) to describe quantum effects in molecular dynamics simulations. In practice, inclusion of quantum effects is important only for a small set of atoms that may be understood as a reduced reaction system coupled to a bath of classical nuclei. As a result, the system could be described with a density component for the electrons and another one for the quantum nulei, both subjected to the external field arising from the classical nuclei, as in the conventional molecular dynamics. The implementation will be a modification of the SIESTA package and the methodology should be applied to simple proton transfer systems, such as protonated water clusters and malonaldehyde, and also to the description of impurities (especially hydrogen) in gold nanowires. The theory is very flexible and in the future may be employed in studies of electron-positron systems. (AU)