[1] Univ Oxford, Clarendon Lab, Ctr Quantum Computat, Oxford OX1 3PU, England
[2] Univ Oxford, Dyson Perrins Lab, Oxford OX1 3QY, England
[3] Univ Oxford, Oxford Ctr Mol Sci, Cent Chem Lab, Oxford OX1 3QH, England
[4] Univ Waterloo, Dept Combinator & Optimizat, Waterloo, ON N2L 3G1, Canada