Fig. 3: Systematic improvability of the CPD backflow ansatz for the water molecule.
From: Simple Fermionic backflow states via a systematically improvable tensor decomposition
Relative ground state correlation energy error (compared to exact diagonalization) for the CPD backflow ansatz (ΨCPD) on the water molecule (6-31G basis, equilibrium geometry as specified in ref. 4) as a function of a support dimension M and b number of configurational samples NS. We also extrapolate these results to infinite M or NS to provide the values in their infinite limit as shown by diamonds. CPD backflow energies are obtained as averages over 50 independent evaluations using the optimized parameters and a sample size of 216, with error bars represented by the standard error across these evaluations.
