Bridging Disciplines: Yiwen Wang’s Journey in Computational Chemistry
2024-25 MolSSI Software Fellow Yiwen Wang did not initially envision a PhD in chemistry, having started her academic journey in the realm of physics. However, being surrounded by friends immersed in chemistry—many of whom later became computational chemists—exposed her to a world where physics, chemistry, biology, and computer science seamlessly intersect in fascinating ways. Daily discussions ranging from quantum chemistry to molecular dynamics ignited her interest in molecular science, ultimately leading her to pursue a Ph.D. in computational and theoretical chemistry.
Her current research focuses on advancing constrained nuclear electronic orbital (CNEO) theory, a framework that incorporates nuclear quantum effects (NQEs) into electronic structure methods. As part of the Prof. Y. Yang group, Yiwen is developing constrained multicomponent time-dependent density functional theory (CNEO-TDDFT) to extend CNEO methodologies from ground-state to excited-state calculations. By integrating NQEs—particularly quantum nuclear delocalization effects—into an effective potential energy surface (PES), her work aims to provide a more accurate description of excited-state dynamics, an area where conventional electronic structure methods often fall short.
The Challenge of Scientific Software Development
Implementing these advanced methodologies in real-world software is no small feat. Under mentorship of MolSSI Software Scientist Dr. Sina Mostafanejad, Yiwen has been working on incorporating the CNEO framework into NWChem and PySCF, two open-source computational chemistry packages written in Fortran and Python, respectively. Despite having no prior experience with Fortran, she embraced the challenge head-on and made substantial contributions to NWChem. She has successfully implemented CNEO ground-state energy and its analytic gradients, as well as CNEO excited-state energy and its analytic gradients. While further refinements remain—such as integrating the framework into NWChem’s workflow, optimizing code structure, and finalizing the compilation process—she anticipates that by the end of her MolSSI Fellowship, the full CNEO functionalities will be implemented and ready for broader use. This will enable researchers studying systems with significant NQEs to leverage CNEO-based methods in their calculations.
A Defining Accomplishment: Turning 40 Pages of Theory into Code
Among her many achievements, one stands out as a particularly defining moment. The successful execution of her code for calculating analytic gradients was the culmination of months of work and theoretical derivations spanning over 40 pages. Seeing those equations come to life in functional computational code was an incredibly rewarding experience—one that still brings her a deep sense of satisfaction.
Beyond Research: A Love for Cooking, Baking, and Nature
While Yiwen’s research keeps her engaged in the world of molecular science, she finds balance in everyday joys. She has a hidden talent for cooking and baking, with a particular fondness for making chocolate or blueberry bagels on weekends. Long walks along the lakeshore of the University of Wisconsin campus provide moments of reflection and connection, often accompanied by phone calls with family and friends.
Looking Ahead: Future Goals and Aspirations
As she continues her Ph.D. journey, Yiwen remains focused on exploring new chemistry problems, conducting impactful research, and ultimately completing her doctoral studies. Whether in academia or industry, her passion lies in developing computational tools that enhance our understanding of molecular systems, with potential applications in drug design, materials science, and beyond.
Through a unique blend of theoretical insight, software development, and interdisciplinary collaboration, Yiwen Wang is making strides in computational chemistry—bringing molecular science and computing together to push the boundaries of what’s possible.