PROJECTS
Development of a linear-scaling MP2 method for large molecules by rigorous integral criteria
PRINCIPAL INVESTIGATOR
 |
Prof. Dr.
Christian Ochsenfeld Eberhard-Karls-Universität Tübingen Institut für Physikalische und Theoretische Chemie Auf der Morgenstelle 8 |
PROJECT RESEARCH ASSISTANT
ABSTRACT
Electron-correlation and in particular dispersion-type effects are crucial for
the quantum-chemical calculation of many molecular systems. However, the
computational effort of even the simplest ab initio approach accounting for
these effects - second-order Møller-Plesset perturbation theory (MP2) -
scales with the fifth power of molecular size, which prohibits the application
of conventional approaches to more than 50-100 atoms. Therefore, the
reduction of the scaling is crucial. Although impressive progress has been
made by several groups towards this goal, there has been so far no rigorous
way of preselecting numerically significant contributions to the correlation
energy, so that either ad-hoc assumptions influencing the accuracy were
necessary or the prefactors of the computational effort have been too large.
In our work, we have introduced the first rigorous upper bounds (multipole-based
integral estimates; MBIE) which allow to preselect the significant
contributions to the MP2 energy without further assumptions. In this way, the
same accuracy and reliability as in conventional approaches is guaranteed,
combined with the possibility to attain a linear-scaling computational
behavior. Based on this idea, the main goal of the present research proposal
is the development of a linear-scaling MP2 method, which allows for the
reliable computation of MP2 energetics for molecules with 500-1000 and
more atoms (without symmetry), so that dispersion-type interactions can be
accounted for in large molecular systems.
07071/2978745 
07071/295490 