Fig 1.
Convergence of the H2 ground state energy with basis set expansion.
The calculations are ordered with increasing Hamiltonian matrix size. The matrices were diagonalized directly (red) and using the QAE + Ocean qbsolv (green) or QAE + Mukai QUBO solver (blue) approaches. The error is given relative to the energy of def2-QZVP reference diagonalization, which has the lowest value among all calculations. The Mukai QUBO solver outperforms the Ocean qbsolv throughout all basis sets by a significant margin.
Table 1.
Electronic ground state energy errors in kcal/mol.
Table 2.
Electronic transition energies of the H2O molecule computed using the QAE and FCI/STO-3G matrix in kcal/mol.
Fig 2.
Potential energy curve of H3+ computed at FCI/cc-PVDZ level.
The same methods as in Fig 1 (same colors) were used. Molecular images (taken at black points) show how the minimum geometry evolves as a function of the distance between two terminal hydrogens. QAE + Mukai QUBO solver curve (blue) overlaps with the reference diagonalization curve and is made dashed, so that both curves are visible.