Coupled Cluster Theory Thesis
This requires a detailed understanding of the asymptotic behaviour of many-particle Coulomb systems near coalescence points of particles.Singular analysis provides a convenient framework to study the asymptotic behaviour of wavefunctions near these singularities.The coupled cluster approach has emerged as the method of choice in ab initio quantum chemistry for the accurate and efficient inclusion of electron correlation beyond the Hartree-Fock approximation.Conventional ground-state coupled cluster theory can be immediately applied to electronic states which are the lowest-energy of a given spin and spatial symmetry.
This corresponds to the construction of an approximate inverse of a Hamiltonian operator with remainder given by a so-called Green operator.
It is hoped that this method, where cluster amplitudes and spinorbitals are fully (bi)variational, may give good results for multireference-type systems. She obtained her MSc titled "Vibrational motion in molecules" from the Norwegian University of Science and Technology (NTNU) in 2014.
After a few years working as a Project Engineer at Hydro in Årdal, she returned to theoretical chemistry, moving to Oslo and starting her Ph D fellowship at the BIVAQUM project in fall 2016.
The Green operator encodes essential asymptotic information and we present as our main result an explicit asymptotic formula for this operator.
First applications to many-particle models in quantum chemistry are presented in order to demonstrate the feasibility of our approach.