Improving Potential Energy Surfaces Using Experimental Feshbach Resonance Tomography.
Abstract
The structure and dynamics of a molecular system is governed by its potential energy 
surface (PES), representing the total energy as a function of the nuclear coordinates. 
Obtaining accurate potential energy surfaces is limited by the exponential scaling of Hilbert 
space, restricting quantitative predictions of experimental observables from first principles 
to small molecules with just a few electrons. Here, we present an explicitly physics-informed 
approach for improving and assessing the quality of families of PESs by modifying them 
through linear coordinate transformations based on experimental data. We demonstrate 
this "morphing" of the PES for the He-H?? complex for reference surfaces at three different 
levels of quantum chemistry and using recent comprehensive Feshbach resonance(FR) 
measurements. In all cases, the positions and intensities of peaks in the collision cross-
section are improved. We find these observables to be mainly sensitive to the long-range 
part of the PES.