Xinyou Ma

Postdoctoral Research Associate - Computational Chemist


Dr. Xinyou Ma (Ma,X.) is a computational chemist who studies the chemical reaction mechanisms and reaction dynamics using a wide range of theoretical simulation methods, including quantum mechanics, semiclassical theory, reaction scattering trajectory methods, transition state theory (TST), molecular dynamics simulations, force field development, free energy calculations, and enhanced sampling methods. With these skillsets, Dr. Xinyou Ma has gained fundamental understanding of 1) gas-phase reaction dynamics, 2) reaction free energy in condensed phase, 3) micro-solvated reactions at the vapor/solid interfaces, 4) reaction dynamics at the gas/solid interfaces, and 5) proton- and ion-transport under the confinement effect.

At ORNL, Dr. Xinyou Ma joins the effort for developing clean energy and decarbonization reactions via computational and theoretical chemistry approaches. Dr. Xinyou Ma's works successfully reveal the stepwise reaction mechanisms of atmospheric CO2 removal using amino acid solutions. Furthermore, Dr. Xinyou Ma studies the excited state reaction mechanism of photo-active materials, which enables clean energy applications in future decarbonization deployments.

At ORNL, Dr. Xinyou Ma also implements the idea of "HPC in the Cloud", which aims to build a stable HPC environment (environmental modules, SLURM, Grafana, and etc.) that is customized for a specific research group. The HPC libraries and scientific computing packages, especially for computational chemistry researchers, are highly optimized based on years of HPC and research experiences. Many help and in collaboration with the ORNL Research Cloud (ORC) team led by Chris Layton.


  1. Ma, X.; Roy, S.; Bryantsev, V. Reaction Mechanism and Rate Limiting Steps of CO2 Capture by Aqueous Glycine: An Ab Initio Free Energy Study. Cell Report Phys. Sci., 2023. Accepted.
  2. Hack, J. H.; Ma, X.; Chen, Y.; Nicholas, L. H. C.; Dombrowski, J. P.; Li, C.; Kung, H. H.; Voth, G. A.; Tokmakoff., A. Proton Dissociation and Delocalization Under Stepwise Hydration of Zeolite HZSM-5. J. Phys. Chem. C, 2023, 127, 16175-16186.
  3. Dang, D.-K.; Ma, X.; Einkauf, J. D.; Ma, Y.-Z.; Custelcean, R.; Moyer, B. A.; Zimmerman, P. M.; Bryantsev, V. S. Photoisomerization Mechanism of Iminoguanidinium Receptors from Spectroscopic Methods and Quantum Chemical Calculations. In submission.
  4. Ma, X.; Hack, J. H.; Dombrowski, J. P.; Chen, Y.; Kung, H. H.; Tokmakoff., A.; Voth, G. A. Hydrated Excess Protons in Zeolite Channels. In preparation.
  5. Brann, M.; Ma, X.; Sibener, S. J. Differential Condensation of Methane Isotopologues in Non-Equilibrium Collisions Modeled with Chemical Dynamics Simulations. J. Phys. Chem. A, 2021, 125, 9405-9413.
  6. Brann, M.; Hansknecht, S. P.; Ma, X.; Sibener, S. J. Differential Condensation of Methane Isotopologues Leading to Isotopic Enrichment Under Non-Equilibrium Gas-Surface Collision Conditions. J. Phys. Chem. A, 2021, 42, 9405-9413 (125 year special issue).
  7. Zhao, C.; Ma, X.; Wu, X.; Thomsen, D. L. Bierbaum, V. M.; Xie, J. Single Solvent Molecules Induce Dual Nucleophiles in Gas-Phase Ion-Molecule Nucleophilic Substitution Reactions. J. Phys. Chem. Lett., 2021, 12, 7134–7139.
  8. Hack, J. H.*; Dombrowski, J. P.*; Ma, X.*; Chen, Y.; Nicholas, L. H. C.; Carpenter, W. B.; Li, C.; Voth, G. A.; Kung, H. H.; Tokmakoff., A. Structural Characterization of Protonated Water Clusters Confined in HZSM-5 Zeolites. J. Am. Chem. Soc., 2021, 143, 10203-10213. (*: Equal contribution.)
  9. Barry, E.; Burns, R.; Chen, W.; De Hoe, G. X.; De Oca, J. M. M.; de Pablo, J. J.; Dombrowski, J. P.; Elam, J. W.; Felts, A. M.; Galli, G.; Hack, J.; He, Q.; He, X.; Hoenig, E.; Iscen, A.; Kash, B.; Kung, H. H.; Lewis, N. H. C.; Liu, C.; Ma, X.; Mane, A.; Martinson, A. B. F.; Mulfort, K. L.; Murphy, J.; Mølhave, K.; Nealey, P.; Qiao, Y.; Rozyyev, V.; Schatz, G. C.; Sibener, S. J.; Talapin, D.; Tiede, D. M.; Tirrell, M. V.; Tokmakoff, A.; Voth, G. A.; Wang, Z.; Ye, Z.; Yesibolati, M.; Zaluzec, N. J.; Darling, S. B. Advanced Materials for Energy-Water Systems: The Central Role of Water/Solid Interfaces in Adsorption, Reactivity, and Transport. Chem. Rev., 2021, 121, 9450-9501.
  10. Ma, X.; Li, C.; Martinson, A. B. F.; Voth, G. A. Water-Assisted Proton Transport in Confined Nanochannels. J. Phys. Chem. C, 2020, 124, 16186–16201.
  11. Kaiser, A.; Jayee, B.; Yao, Y.; Ma, X.; Wester, R.; Hase, W. L. Time-Dependent Perspective for the Intramolecular Couplings of the N–H Stretches of Protonated Tryptophan. J. Phys. Chem. A, 2020, 124, 4062-2067.
  12. Jayee, B.; Malpathak, S.; Ma, X.; Hase, W. L. Is CH3NC isomerization an intrinsic non-RRKM unimolecular reaction? J. Chem. Phys., 2019, 151, 184110.
  13. Li, Y.; Ma, X.; Weber, J. Interaction between γC87 and γR242 residues participates in energy coupling between catalysis and proton translocation in Escherichia coli ATP synthase. Biochim. Biophys. Acta, Bioenergetics, 2019, 1860, 679-687.
  14. Pratihar, S.; Muniz, M. C. N. B.; Ma, X.; Borges, I.; Hase, W. L. Pronounced changes in atomistic mechanisms for the Cl + CH3I SN2 reaction with increasing collision energy. Phys. Chem. Chem. Phys., 2019, 21, 2039-2045.
  15. Ma, X.; Di Liberto, G.; Conte, R.; Hase, W. L.; Ceotto, M. A quantum mechanical insight into SN2 reactions: Semiclassical Initial Value Representation calculations of the vibrational features of the Cl- + CH3Cl pre-reaction complex with VENUS suite of codes. J. Chem. Phys., 2018, 149, 164113.
  16. Malpathak, S.; Ma, X.; Hase, W. L. Addressing an Instability in Unrestricted Density Functional Theory Direct Dynamics Simulations. J. Comput. Chem., 2019, 40, 933-936.
  17. Ma, X.; Yang, N.; Johnson, M.; Hase, W. L. Anharmonic Density of States for Vibrationally Excited I-(H2O), (H2O)2, and I-(H2O)2. J. Chem. Theory Comput., 2018, 14, 3986-3997.
  18. Ozhukil Kollath, V.; Liang, Y.; Mayer, F. D.; Ma, X.; Korzeniewski, C.; Karan, K. Model Based Analyses of Confined Polymer Electrolyte Nanothin Films Experimentally Probed by Polarized ATR-FTIR Spectroscopy. J. Phys. Chem. C, 2018, 122, 9578-9585.
  19. Malpathak, S.; Ma, X.; Hase, W. L. Direct Dynamics Simulations of the Unimolecular Dissociation of Dioxetane. Probing the Non-RRKM Dynamics. J. Chem. Phys., 2018, 148, 164309.
  20. Bhandari, H. N.; Ma, X.; Paul, A. K.; Smith, P.; Hase, W. L. Particle Swarm Optimization (PSO) Methods for Fitting an Analytic Potential Energy Function: Application on I-(H2O). J. Chem. Theory Comput., 2018, 14, 1321-1332.
  21. Pratihar, S.; Ma, X.; Xie, J.; Scott, R.; Gao, E.; Ruscic, B.; Aquino, A. J. A.; Setser, D. W.; Hase, W. L. Post-Transition State Dynamics and Product Energy Partitioning Following Thermal Excitation of the F HCH2CN Transition State: Disagreement with Experiment. J. Chem. Phys., 2017, 147, 144301.
  22. Ma, X.; Tan, X.; Hase, W. L. Effects of Vibrational and Rotational Energies on the Lifetime of the Pre-Reaction Complex for the F + CH3I SN2 Reaction. Int. J. Mass Spectrom., 2018, 429, 127-135.
  23. Ma, Y.-T.; Ma, X.; Li, A.; Guo, H.; Yang, L.; Zhang, J.; Hase, W. L. Potential Energy Surface Stationary Points and Dynamics of the F + CH3I Double Inversion Mechanism. Phys. Chem. Chem. Phys. 2017, 19, 20127-20136.
  24. Ma, X.; Hase, W. L. Perspective: Chemical Dynamics Simulations of Non-Statistical Reaction Dynamics. Phil. Trans. R. Soc. A, 2017, 375, 20160204.
  25. Pratihar, S.; Ma, X.; Homayoon, Z.; Barnes, G. L.; Hase, W. L. Direct Chemical Dynamics Simulation. J. Am. Chem. Soc., 2017, 139, 3570-3590.
  26. Yang, L.; Zhang, J.; Xie, J.; Ma, X.; Zhang, L.; Zhao, C.; Hase, W. L. Competing E2 and SN2 Mechanisms for the F + CH3CH2I Reaction. J. Phys. Chem. A, 2017, 121, 1078-1085.
  27. Xie, J.*; Ma, X.*; Zhang, J.; Hierl, P. M.; Viggiano, A. A.; Hase, W. L. Effect of Microsolvation on the OH(H2O)n + CH3I Rate Constant. Comparison of Experiment and Calculations for OH(H2O)2 + CH3I. Int. J. Mass Spectrom., 2017, 418, 122-129. (*: Equal contribution.)
  28. Ma, X.; Paul, A. K.; Hase, W. L. Chemical Dynamics Simulations of Benzene Dimer Dissociation. J. Phys. Chem. A, 2015, 119, 6631-6640.

Postdoctoral Scholar, University of Chicago, 2018-2022

Ph.D., Chemistry, Texas Tech University, Lubbock, TX, USA, 2018

B.S., Applied Chemistry, Beijing University of Chemical Technology, Beijing, China, 2012