Quantum Few-Body Problem

This research project concerns recent advances in the application of explicitly correlated Gaussians toward accurate (spectroscopic accuracy, i.e. nano-Hartree) numerical calculations of bound state energies, angular momentum, and pair correlation functions.

The development of high-level quantum-mechanical methods with explicitly correlated functions provides new grounds for the verification of the theoretical models and for the assessment of their limitations. In atomic molecular physics, for example, an accurate solution of the few-body problem is desirable to validate effective approximate fixed-nuclei models for the description of the ground and near-dissociation states that consider corrections to the BO approximation. Furthermore, comparing theoretical and experimental data, it is possible to accurately determine the values of fundamental constants, nuclear charge radii, nuclear quadrupole moments, and other quantities. High-accuracy theoretical methods also serve as an important source of ideas and technical solutions for the development of other approximate approaches applicable to larger systems.