Parallel quantum chemistry on noisy intermediate-scale quantum computers

A parallel hybrid quantum-classical algorithm for the solution of quantum-chemical ground-state energy problem on gate-based quantum computers is presented. This approach based reduced density-matrix functional theory (RDMFT) formulation electronic structure problem. For that purpose, full system decomposed into an indirectly coupled sum functionals all its subsystems using adaptive cluster approximation to RDMFT. The approximations involved in decomposition and itself can be systematically converged exact result. solutions effective involves a constrained minimization over many-particle states are approximated by parametrized trial computer similarly variational eigensolver. independence introduces new level parallelization allows computational treatment much larger molecules with given qubit count. In addition, proposed techniques presented reduce count, number programs, as well depth. evaluation essential part our demonstrated Hubbard-like systems IBM superconducting transmon qubits.