Implicit solvent sample-based quantum diagonalization

TL;DR

This paper extends the sample-based quantum diagonalization (SQD) method to include solvent effects via the IEF-PCM model, enabling more realistic simulations of molecules in solution on quantum hardware.

Contribution

It introduces the integration of IEF-PCM solvent modeling into SQD, allowing quantum simulations of solvated molecules, and demonstrates scalability on multiple quantum devices.

Findings

Successful SQD IEF-PCM simulations of various molecules in aqueous solution.

Scalability demonstrated on quantum devices with up to 52 qubits.

Comparison with classical CASCI results shows promising accuracy.

Abstract

The sample-based quantum diagonalization (SQD) method shows great promise in quantum-centric simulations of ground state energies in molecular systems. Inclusion of solute-solvent interactions in simulations of electronic structure is critical for biochemical and medical applications. However, all of the previous applications of the SQD method were shown for gas-phase simulations of the electronic structure. The present work aims to bridge this gap by introducing the integral equation formalism polarizable continuum model (IEF-PCM) of solvent into the SQD calculations. We perform SQD/cc-pVDZ IEF-PCM simulations of methanol, methylamine, ethanol, and water in aqueous solution using quantum hardware and compare our results to CASCI/cc-pVDZ IEF-PCM simulations. Our simulations on ibm_cleveland, ibm_kyiv, and ibm_marrakesh quantum devices are performed with 27, 30, 41, and 52 qubits demonstrating the scalability of SQD IEF-PCM simulations.