Integrating Classical and Quantum Software for Enhanced Simulation of Realistic Chemical Systems

TL;DR

This paper presents a hybrid quantum-classical framework that enables large-scale, realistic chemical system simulations, demonstrating near-linear scaling and practical applicability of quantum computing in chemistry.

Contribution

Developed an interface combining quantum circuit simulation with classical software for efficient force evaluation in complex chemical systems.

Findings

Force evaluation scales nearly linearly with system size

Successfully performed geometry optimizations on condensed-phase systems

Demonstrated practical quantum-classical hybrid calculations for realistic chemistry

Abstract

We demonstrate the feasibility of quantum computing for large-scale, realistic chemical systems through the development of a new interface using a quantum circuit simulator and CP2K, a highly efficient first-principles calculation software. Quantum chemistry calculations using quantum computers require Hamiltonians prepared on classical computers. Moreover, to compute forces beyond just single-point energy calculations, one- and two-electron integral derivatives and response equations are also to be computed on classical computers. Our developed interface allows for efficient evaluation of forces with the quantum-classical hybrid framework for large chemical systems. We performed geometry optimizations and first-principles molecular dynamics calculations on typical condensed-phase systems. These included liquid water, molecular adsorption on solid surfaces, and biological enzymes. In water benchmarks with periodic boundary conditions, we confirmed that the cost of preparing second-quantized Hamiltonians and evaluating forces scales almost linearly with the simulation box size. This research marks a step towards the practical application of quantum-classical hybrid calculations, expanding the scope of quantum computing to realistic and complex chemical phenomena.