What is a Computational Chemist?

Vanessa Oklejas is a computational chemist. Photo: Elisa Haber

Aerospace has a reputation for having a collection of distinguished experts who use innovative ways to solve some of the nation’s toughest technical challenges. Dr. Vanessa Oklejas, a member of the technical staff in the Polymers Section of the Micro/Nano Technology Department, is just one such expert. Oklejas is a computational chemist who uses her rarified skill set to help her colleagues gain new perspectives on problems.

Computational chemistry is a field of chemistry that uses mathematics, computers, and computer science to explore chemical problems. It is most often used to help interpret or guide experimental research, but sometimes used in place of experiments when necessary.

“A computational chemist uses computers to study atoms and molecules and how they act and interact. That definition is as short as it is inclusive,” Oklejas explains. “For example, a computational chemist might use numerical calculations to predict molecular structure for a single small molecule. Or, alternatively, a computational chemist might use some form of artificial intelligence in order to predict the interaction of drug molecules with their biological targets — as in the case of rational drug design.”

At Aerospace, computational chemistry is primarily used as a tool to aid in research and experimentation. The detailed molecular information provided by computational research is used to help interpret results from experiments or to guide future experimentation.

“It’s often helpful to use simulations or quantum mechanical calculations in order to form a detailed mental picture of what might be occurring during an experiment on a molecular level, which, in turn, influences microscopic and macroscopic behavior,” Oklejas says.

The insight gained from computational research may help to decrease the time it takes for experiments to provide substantive results that can be used to address problems encountered in the real world.

Computational chemistry is particularly useful in materials science.

“There is a considerable array of computational tools for predicting material properties,” Oklejas explains. “For example, molecular dynamics simulations are frequently used to simulate a range of molecular properties and the results of these simulations can be used to calculate static and dynamic macroscopic quantities, such as tensile strength or thermal conductivity.”

In some cases, computational chemistry might provide the only avenue for scientists at Aerospace to gain data about projects they are working on. If a particular experiment cannot be done due to lack of resources, computational chemistry can be an alternative source of information where there otherwise would be none.

Oklejas says that she became interested in computational chemistry when she was a graduate student studying phenomena on electrode surfaces using Raman spectroscopy.

“I started to use quantum mechanical calculations to help interpret my experimental results and it turned out that the calculations allowed me to view some of my experiments in a totally new light.”

She joined the corporation in March of 2011.

As computers continue to become more powerful, they will increasingly be a resource for helping to solve challenging scientific problems. At Aerospace, computational chemistry is one tool in the corporation’s large tool box that, when integrated properly into a strategic plan, can provide an efficient and economical approach to solving tough problems.

—Allison Barker