QC Ware, IonQ Test Hybrid Quantum Chemistry Workflow

On September 1, QC Ware and IonQ announced they had performed a hybrid quantum-classical chemistry calculation on a model of the cytochrome P450nor active site. The results matched classical benchmarks within 0.5 kcal/mol. This work utilized a four-orbital active space mapped onto eight qubits on IonQ’s Forte trapped-ion system, with significant preparatory work handled by classical GPUs. This demonstration reproduces known results and is not a computation beyond the capabilities of classical machines.

Details of the Experiment

According to the September 1 press release, the setup integrated QC Ware’s Promethium platform with IonQ’s Forte, accessed via Amazon Braket. Promethium initially constructed a 115-atom model of the P450nor active site, comprising over 1,000 molecular orbitals. The strongly correlated portion was then reduced to four orbitals on eight qubits. Forte measured this smaller segment in a single basis, returning the data to Promethium for the classical completion of the energy calculation.

The reported outcome falls within 0.5 kcal/mol of classical benchmarks, meeting the 1 kcal/mol threshold chemists refer to as chemical accuracy. QC Ware claims this outperforms the standard classical mean-field method by more than a factor of two. However, this comparison is against a deliberately weaker baseline. The stronger classical methods that established the benchmark were still responsible for validating the results here, making it inaccurate to claim quantum advantage.

An eight-qubit system with a four-orbital active space represents a small-scale demonstration. It confirms the workflow’s compatibility across different hardware types, building on QC Ware’s previous tests on other quantum machines. Kin-Joe Sham, QC Ware’s co-founder and COO, emphasized flexibility over performance as the key takeaway.

QC Ware stated that the workflow’s approach to combining classical and quantum computing is hardware-agnostic.

Neither company has released a peer-reviewed paper on this experiment. The 0.5 kcal/mol figure, the qubit mapping, and the claim of a 20x speed improvement for Promethium’s classical mode are all sourced from QC Ware’s own press release. Amazon Web Services provided cloud compute credits to support the demonstration.

Relevance to Drug Discovery Claims

The proposition is that improved electrostatic interaction energies at metal centers, such as the iron site in P450nor, could aid in ranking drug candidates and identifying metabolic risks earlier in development. Cytochrome P450 enzymes are crucial for much of human drug metabolism, making the chosen target relevant. IonQ’s Scott Millard referred to it as “real quantum impact on real health outcomes,” a statement that extends beyond the scope of an eight-qubit test on a single active site.

This work remains in the research phase until larger systems can be modeled and the methodology is validated against experimental data. Though QC Ware markets Promethium as currently available, the quantum component remains a demonstration.