Molecular properties

Viktor N. Staroverov

Niels Henrik David Bohr

Ivan Kassal, Alán Aspuru‐Guzik

Quantum computers, if available, could substantially accelerate quantum simulations. We extend this result to show that the computation of molecular properties (energy derivatives) could also be sped up using quantum computers. We provide a quantum algorithm for the numerical evaluation of molecular properties, whose time cost is a constant multiple of the time needed to compute the molecular energy, regardless of the size of the system. Molecular properties computed with the proposed approach could also be used for the optimization of molecular geometries or other properties. For that purpose, we discuss the benefits of quantum techniques for Newton's method and Householder methods. Finally, global minima for the proposed optimizations can be found using the quantum basin hopper algorithm, which offers an additional quadratic reduction in cost over classical multi-start techniques.

Niels Henrik David Bohr

G. K. Vemulapalli

By taking molecules and atoms as models for wholes and parts, I explore the relation between the atomic and molecular properties in this article. Molecular properties do not reduce to atomic properties in the sense the former cannot be obtained by adding or multiplying the latter. However, quantum states of molecules are obtained from the quantum states of atoms by addition and multiplication. Because molecular properties are calculated reliably from the atomic states in quantum theory, it may be claimed that property reduction has been accomplished successfully. I show that such reduction entails underlying holism.

NORMAN R. CAMPBELL