Book Image

Quantum Chemistry and Computing for the Curious

By : Alex Khan, Keeper L. Sharkey, Alain Chancé
Book Image

Quantum Chemistry and Computing for the Curious

By: Alex Khan, Keeper L. Sharkey, Alain Chancé

Overview of this book

Explore quantum chemical concepts and the postulates of quantum mechanics in a modern fashion, with the intent to see how chemistry and computing intertwine. Along the way you’ll relate these concepts to quantum information theory and computation. We build a framework of computational tools that lead you through traditional computational methods and straight to the forefront of exciting opportunities. These opportunities will rely on achieving next-generation accuracy by going further than the standard approximations such as beyond Born-Oppenheimer calculations. Discover how leveraging quantum chemistry and computing is a key enabler for overcoming major challenges in the broader chemical industry. The skills that you will learn can be utilized to solve new-age business needs that specifically hinge on quantum chemistry
Table of Contents (14 chapters)
8
Chapter 8: References
9
Chapter 9:Glossary
Appendix B: Leveraging Jupyter Notebooks on the Cloud
Appendix C: Trademarks

Chapter 5: Variational Quantum Eigensolver (VQE) Algorithm

“Not only is the Universe stranger than we think, it is stranger than we can think.”

– Werner Heisenberg

Figure 5.1 – Steepest descent line on a potential energy surface (PES) [authors]

We introduced the history behind the use of the variational method in Section 1.1, Understanding the history of quantum chemistry and mechanics. It is a mathematical construct that can be used computationally. Within the context of quantum chemistry, the variational method is used to determine the lowest energy associated with an eigenvalue, either the ground state or excited states.

The Variational Quantum Eigensolver (VQE) algorithm was introduced in 2014 [VQE_1] and is defined using quantum-based hardware. It is the first of several Variational Quantum Algorithms (VQAs) that are currently being explored by the scientific industry.

We use Unitary Coupled Cluster Singles and...