John H. Hymel

PhD Graduate Student, School of Chemistry and Biochemistry, Georgia Institute of Technology
Mailing Address: School of Chemistry and Biochemistry, Georgia Tech, 901 Atlantic Drive, NW., Atlanta, GA 30332
Email: jhymel6@gatech.edu
Office: MoSE 4202
This page: https://jhymel.github.io/

For more information, check out my CV, Linkedin, GitHub, or ORCID ID.

Background and current work

As of 2022, I am a third-year chemistry graduate student at the Georgia Institute of Technology where I work under the advisement of Dr. Jesse McDaniel. My current research involves studying how electrochemical processes are modulated by choice of electrolyte near electrochemical interfaces. Part of my work has involved studying how double-layer induced ion-pairing effects modulate oxidation-reduction potentials. While my more recent work used DFT-based QM/MM to determine how the thermodynamics, kinetics, and selectivity of olefin cyclization reactions are modulated by choice of electrolyte and the electrical double layer.

I recieved my B.S. in Chemistry from the University of Tennessee where I performed research under the advisement of Dr. Konstantinos Vogiatzis. During the spring of 2020, I participated in the Higher Education Research Experience (HERE) for post-bachelor's program at the Nanomaterials Theory Institute at Oak Ridge National Laboratory under the direction of Dr. Bobby Sumpter.

My current research interests primarily fall into the area of electrochemistry while I generally make use of molecular simulation and electronic structure methods. So far, I have worked on projects involving CO₂ capture, gas separations, electron-beam/matter interactions, and redox reactions. While studying these applications, I have utilized several computational methods including classical molecular dynamics, ab initio molecular dynamics, fixed-voltage molecular dynamics, density functional theory, symmetry adapted perturbation theory, and coupled-cluster theory. More recently, I've become interested in enhanced sampling methods and have been using Plumed in order to perform umbrella sampling, well-tempered metadynamics, and well-sliced metadynamics.

The majority of my programming experience has involved writing Python and shell scripts to automate computations and simulations run in high performance computing environments where the heavy-lifting for these calculations is done in C/C++/Fortran by software packages such as OpenMM, Psi4, NWChem, and TurboMole.

Publications

(1)

Townsend, J.; Micucci, C. P.; Hymel, J. H.; Maroulas, V.; Vogiatzis, K. D. Representation of Molecular Structures with Persistent Homology for Machine Learning Applications in Chemistry. Nat Commun 2020, 11 (1), 3230. https://doi.org/10.1038/s41467-020-17035-5.

Structures, energies, and code available at https://gitlab.com/voglab/PersistentImages_Chemistry.

(2)

Hymel, J. H.; Townsend, J.; Vogiatzis, K. D. CO₂ Capture on Functionalized Calixarenes: A Computational Study. J. Phys. Chem. A 2019, 123 (46), 10116–10122. https://doi.org/10.1021/acs.jpca.9b08670.

Structures and energies available at https://github.com/jhymel/CalixareneXYZ.

Gallery

Ab initio