# Shaping the Future of Humanity, One Atom at a Time

## Quantum computing provides the answers to the opaque world of quantum chemistry — answers that will transform our world

Quantum computing is an exponential technology that has the capability to solve some of the biggest problems facing humanity. One of the first fields which will benefit from this emerging field is that of *quantum chemistry*.

Quantum chemistry is concerned with the underlying behaviours of atoms and molecules, and what happens behind the scenes during a chemical reaction or process. Quantum chemistry revolves around the principles of **quantum mechanics** — the mechanics of the atomic and subatomic.

Quantum particles are inherently *probabilistic*. According to the **Heisenberg Uncertainty Principle**, we can never simultaneously know both the *position* and the *momentum* of an electron. Instead, we can only describe the *probability *of finding an electron in a specific region (an **orbital **for an atom) via the **Shrödinger Wave Equation**. This is a *partial differential equation*, which, upon solving, gives us a function that provides us with the probability.

In chemistry, the properties of atoms, as well as molecules and reactions are primarily determined by electrons and their interactions, so quantum chemistry is fundamental to understanding the *why* and *how*. And this is where the power of quantum computing comes in.

Nature isn’t classical, dammit, and if you want to make a simulation of nature, you’d better make it quantum mechanical, and by golly it’s a wonderful problem, because it doesn’t look so easy.

— Richard Feynman

Quantum computing operates on the principles of quantum mechanics, rather than classical physics and information theory. Quantum computing revolves around the manipulation of **quantum bits**, or **qubits**. Quantum bits are *quantum particles* (generally electrons or photons), and hence inherit all of their quantum weirdness which allows for some incredible possibilities.

Quantum chemistry is pivotal for understanding atomic & molecular interactions and their various chemical processes. These interactions are inherently *quantum*, but due to the complexity and exponential scaling of quantum variables and statistics, it is impossible for even the best classical computers to determine a solution to all but the smallest systems. Quantum computers provide a solution.

Some of the applications of quantum computers within quantum chemistry include the exploration of next-gen materials for batteries, which could have key implications across the automotive and energy sectors; drug discovery for diseases; the accurate modelling of biological processes and protein interactions. Accurate predictions from computers regarding chemical processes “can unlock new frontiers in chemistry, improving a wide variety of industries” *(N.Rubin and C.Neill, 2020)*.

Google AI, after having demonstrated quantum supremacy in 2019, performed the largest chemical simulation ever performed on a quantum computer. The Google AI team accurately simulated the energy state of a molecule with 12 hydrogen atoms, with a qubit representing each electron. They also were able to model a chemical reaction in a simple molecule, a simulation dubbed the **Hartree-Fock procedure**.

Consider the implications for even more complicated molecules and reactions; quantum systems simulated by such systems themselves. Quantum computing will revolutionize the pharmaceutical industry, the renewable energy sector, and lead to advancements in a myriad of fields. Quantum computing will pave the way to the future of humanity.