Accurate wave functions for multi-sorted quantum  systems

Michael Pak

(Department of chemistry, University of Illinois at Urbana-Champaign)

Abstract

I will discuss various mathematical issues that arise in describing ground state wave functions of systems with more than one kind of quantum particles.  Depending on the mass ratio of particles involved, there are two essentially distinct regimes that need to be considered, each leading to its own set of computational problems.  When mass disparity is large and the Born-Oppenheimer separation is satisfied reasonably well, the difficulties in describing the adiabatic wave function in an orbital-based method appear to be yet unresolved. I will demonstrate the deficiencies of currently available orbital based approaches for describing electron-nuclear quantum systems, and review some mathematical problems that need to be addressed.