quantum-computingCleveland Clinic, RIKEN, and IBM Cross 12,000-Atom Barrier in Heterogeneous Quantum-Classical Drug Binding Simulations
Systems investigated (A), overarching algorithmic scheme adopted, (B), representation of a fragment (C), and details of the lower scaling fragment construction (D) introduced in this work. We performed workflow automation on computational tasks in panel B (red dashed frame). A research collaboration spanning the Cleveland Clinic Foundation, the RIKEN Center for Computational Science, and IBM Quantum has executed the largest heterogeneous quantum-classical (HQC) electronic-structure calculation to date, simulating full solvated protein–ligand complexes exceeding 12,000 atoms. Detailed in a technical preprint on arXiv, the team paired two 156-qubit IBM Heron r2 processors with three leadership supercomputers to collect 3.0 billion measurement shots across 21,006 circuits, achieving a greater than 40× increase in molecular size and up to a 210× improvement in fragment energy accuracy over previous quantum-embedding benchmarks. 12,635-Atom HQC Biomolecular Simulation Campaign ProfileSystem DimensionExperimental SpecificationTechnical & Computational BenchmarkTarget BiomoleculesTrypsin–benzamidine (12,635 atoms) & T4-lysozyme–n-butyl-benzene (11,608 atoms)Up to 31,795 molecular orbitals in solvated environments; >40× larger than prior 303-atom Trp-cage benchmark.Quantum HardwareTwo 156-qubit IBM Heron r2 QPUs (ibm_cleveland & ibm_kobe)21,006 circuits executed using up to 94 active qubits over 239+ QPU hours, gathering 3.0 × 109 samples.Classical HPC SystemsFugaku (152,064 nodes), Miyabi-G (1,104 GH200 nodes), & ROQUO (126 GB200 nodes)Distributed GPU-accelerated Selected-Basis Diagonalization (SBD-G) reaching 72.5% strong-scaling parallel efficiency.Fragment Solver AccuracyTrimSQD & O(1)-scaling Embedded Wavefunction (EWF)0.10 mHa deviation vs. DMRG on trypsin’s largest 45-orbital fragment (210× accuracy gain over ExtSQD).Biochemical DeliverableFirst HQC protein–ligand binding energy predictionMixed-basis (3-21G / STO-3G) workflow resolved T4-lysozy