Fig. 2. DMET–ESVQE simulated homogeneous stretching of an evenly spaced hydrogen chain composed of 10 atoms in (a) STO-3G and (b) 6-31G basis sets, in comparison with RHF, CCSD and FCI results. The MRCI + Q + F12@CBS results in both panels can be considered as the exact reference in the complete basis set (CBS) limit.⁷⁴ For the STO-3G basis set, we also show the results obtained by conventional ESVQE. The grey horizontal line indicates the exact dissociation limit composed of non-interacting hydrogen atoms.