Lab Fellow, Computational Scientist
Advanced Computing, Math & Data
Lab Fellow, Computational Scientist
Advanced Computing, Math & Data

Dr. Sotiris Xantheas is known in the chemical physics scientific community for his research in intermolecular interactions in aqueous ionic clusters and the use of ab-initio electronic structure calculations to elucidate their structural and spectral features. His research has ranged from the computation of potential energy surfaces for various chemical reactions using correlated wavefunctions to the elucidation of reaction paths governing carbene ring opening processes and the location and characterization of intersections of potential energy surfaces of the same symmetry in polyatomic systems. He has recently utilized the results of high-level electronic structure calculations to parametrize a family of ab-initio based interaction potentials for water and used those potentials to simulate the macroscopic properties of liquid water and ice.

Research Interests

  • Structures, vibrational spectra, electric properties and energetics of aqueous clusters
  • Quantitative description of many-body non-additive effects in clusters and condensed phase environments
  • Development of interaction potentials based on first principles to study water, ice and aqueous solvation of ions.

Education and Credentials

  • Postdoctoral fellow, Pacific Northwest National Laboratory, USA
  • Ph.D., Chemistry, Iowa State University, Ames, Iowa, USA
  • Diploma, Chemical Engineering, National Polytechnic University of Athens, Greece

Affiliations and Professional Service

  • American Association for the Advancement of Science (AAAS) Fellow (2010)
  • American Physical Society (APS) Fellow (2005)
  • Institute for Advanced Study, Technical University of Munich at Garching, Visiting Fellow (2012-present)
  • Japan Society for the Promotion of Science (JSPS) Fellow (2011)
  • Elected member, Executive committee, American Chemical Society (ACS), Division of Physical Chemistry (2009-2012)
  • American Chemical Society (ACS) member
  • Institute for Electronic Structure and Laser, Foundation for Research and Technology, Crete, Greece, adjunct member (1996-)
  • Director, NATO Advanced Study Institute on "Recent Theoretical and Experimental Advances in Hydrogen Bonded Clusters," in 1997

Awards and Recognitions

  • Director's Award for Exceptional Scientific Achievement, Pacific Northwest National Laboratory (2013)
  • Advisory Editorial Board, Chemical Physics Letters (2013-2015)
  • Editorial Advisory Board, Journal of Physical Chemistry (2012-2014)
  • Elected Member, Council of Fellows, Pacific Northwest National Laboratory (2009-present)
  • Fellow, American Association for the Advancement of Science
  • Alexander von Humboldt Foundation Award, 2009
  • "Friedrich Wilhelm Bessel" award from the Alexander von Humboldt Foundation in Bonn, Germany, 2003
  • Director's Award for Outstanding Performance, Pacific Northwest National Laboratory (2003)
  • Presented numerous invited talks at academic institutions, research centers and international meetings
  • Fellow, American Physical Society
  • Laboratory Fellow at Pacific Northwest National Laboratory (2004-present)

PNNL Publications


  • Hou G., N. Govind, S.S. Xantheas, and X. Wang. 2018. "Deviation from the trans-Effect in Ligand-Exchange Reactions of Zeise’s Ions PtCl3(C2H4)- with Heavier Halides (Br-, I-)." Journal of Physical Chemistry A 122, no. 5:1209-1214. PNNL-SA-129320. doi:10.1021/acs.jpca.7b10808
  • Mukhopadhyay A., S.S. Xantheas, and R.J. Saykally. 2018. "The water dimer II: Theoretical investigations." Chemical Physics Letters 700. PNNL-SA-130822. doi:10.1016/j.cplett.2018.03.057


  • Douberly G.E., R.E. Miller, and S.S. Xantheas. 2017. "Formation of Exotic Networks of Water Clusters in Helium Droplets Facilitated by the Presence of Neon Atoms." Journal of the American Chemical Society 139, no. 11:4152-4156. PNNL-SA-124847. doi:10.1021/jacs.7b00510
  • Hamm P., G.S. Fanourgakis, and S.S. Xantheas. 2017. "A surprisingly simple correlation between the classical and quantum structural networks in liquid water." Journal of Chemical Physics 147, no. 6:Article No. 064506. PNNL-SA-95712. doi:10.1063/1.4993166
  • Ward T.B., E. Miliordos, P.D. Carnegie, S.S. Xantheas, and M.A. Duncan. 2017. "Ortho-Para Interconversion in Cation-Water Complexes: The Case of V+(H2O) and Nb+(H2O) Clusters." Journal of Chemical Physics 146, no. 22:10.1063/1.4984826. PNNL-SA-124984. doi:10.1063/1.4984826
  • Warneke J., G. Hou, E. Apra, C. Jenne, Z. Yang, Z. Qin, and K. Kowalski, et al. 2017. "Electronic Structure and Stability of [B12X12]2- (X=F-At): A Combined Photoelectron Spectroscopic and Theoretical Study." Journal of the American Chemical Society 139, no. 41:14749-14756. PNNL-SA-125660. doi:10.1021/jacs.7b08598
  • Willow S.Y., and S.S. Xantheas. 2017. "Molecular-Level Insight of the Effect of Hofmeister Anions on the Interfacial Surface Tension of a Model Protein." The Journal of Physical Chemistry Letters 8, no. 7:1574-1577. PNNL-SA-109965. doi:10.1021/acs.jpclett.7b00069
  • Yoo S., and S.S. Xantheas. 2017. "Structures, Energetics and Spectroscopic Fingerprints of Water Clusters n=2-24." In Handbook of Computational Chemistry, Second Edition, edited by J Leszczynski, et al. 1139-1172. Cham:Springer International Publishing. PNNL-SA-126670.doi:10.1007/978-3-319-27282-5_21


  • Chang T., S.S. Xantheas, and A. Vasdekis. 2016. "Mesoscale Polymer Dissolution probed by Raman Spectroscopy and Molecular Simulations." Journal of Physical Chemistry B 120, no. 40:110581-10587. PNNL-SA-118505. doi:10.1021/acs.jpcb.6b05565
  • Iwata S., D. Akase, M. Aida, and S.S. Xantheas. 2016. "Electronic origin of the dependence of hydrogen bond strengths on nearest-neighbor and next-nearest-neighbor hydrogen bonds in polyhedral water clusters (H2O)n, n = 8, 20 and 24." Physical Chemistry Chemical Physics. PCCP 18, no. 29:19746-19756. PNNL-SA-114206. doi:10.1039/C6CP02487D
  • Miliordos E., and S.S. Xantheas. 2016. "The origin of the reactivity of the Criegee intermediate: implications for atmospheric particle growth." Angewandte Chemie International Edition 55, no. 3:1015-1019. PNNL-SA-108385. doi:10.1002/anie.201509685
  • Miliordos E., E. Apra, and S.S. Xantheas. 2016. "A New, Dispersion - Driven Intermolecular Arrangement for the Benzene -Water Octamer Complex: Isomers and Analysis of their Vibrational Spectra." Journal of Chemical Theory and Computation 12, no. 8:4004-4014. PNNL-SA-114248. doi:10.1021/acs.jctc.6b00668
  • Moore J.S., S.S. Xantheas, J.W. Grate, T.W. Wietsma, E. Gratton, and A. Vasdekis. 2016. "Modular Polymer Biosensors by Solvent Immersion Imprint Lithography." Journal of Polymer Science. Part B, Polymer Physics 54, no. 1:98-103. PNNL-SA-112121. doi:10.1002/polb.23961
  • Willow S.Y., X. Zeng, S.S. Xantheas, K.S. Kim, and S. Hirata. 2016. "Why is MP2-Water "Cooler" and "Denser" than DFT-Water?." Journal of Physical Chemistry Letters 7, no. 4:680-684. PNNL-SA-114628. doi:10.1021/acs.jpclett.5b02430
  • Wolke C.T., J.A. Fournier, E. Miliordos, S.M. Kathmann, S.S. Xantheas, and M.A. Johnson. 2016. "Isotopomer-selective spectra of a single intact H2O molecule in the Cs+(D2O)5H2O isotopologue: Going beyond pattern recognition to harvest the structural information encoded in vibrational spectra." Journal of Chemical Physics 144, no. 7:074305. PNNL-SA-114570. doi:10.1063/1.4941285
  • Xantheas S.S. 2016. "Spying on the Neighbors' Pool: Spectral Signatures are Obtained for the Movement of Protons in Cold Water Clusters." Science 354, no. 6316:1101. PNNL-SA-122078. doi:10.1126/science.aal1413


  • Brorsen K.R., S.Y. Willow, S.S. Xantheas, and M.S. Gordon. 2015. "The melting temperature of liquid water with the effective fragment potential." Journal of Physical Chemistry Letters 6, no. 18:3555-3559. PNNL-SA-111832. doi:10.1021/acs.jpclett.5b01702
  • Ebata T., R. Kusaka, and S.S. Xantheas. 2015. "Laser Spectroscopic and Theoretical Studies of the Structures and Encapsulation Motifs of Functional Molecules." In Proceedings of the International Conference of Computational Methods in Sciences and Engineering (ICCMSE 2010), October 3-8, 2010, Kos, Greece. AIP Conference Proceedings, edited by TE Simos and G Maroulis, 1642, 51. Melville, New York:American Institute of Physics. PNNL-SA-75396.doi:10.1063/1.4906630
  • Fournier J.A., C.T. Wolke, M.A. Johnson, T.T. Odbadrakh, K.D. Jordan, S.M. Kathmann, and S.S. Xantheas. 2015. "Snapshots of Proton Accommodation at a Microscopic Water Surface: Understanding the Vibrational Spectral Signatures of the Charge Defect in Cryogenically Cooled H+(H2O)n=2 - 28 Clusters." Journal of Physical Chemistry A 119, no. 36:9425-9440. PNNL-SA-109885. doi:10.1021/acs.jpca.5b04355
  • Imoto S., S.S. Xantheas, and S. Saito. 2015. "Ultrafast dynamics of liquid water: Energy relaxation and transfer processes of the OH stretch and the HOH bend." Journal of Physical Chemistry B 119, no. 34:11068-11078. PNNL-SA-108709. doi:10.1021/acs.jpcb.5b02589
  • Miliordos E., and S.S. Xantheas. 2015. "An accurate and efficient computational protocol for obtaining the Complete Basis Set limits of the binding energies of water clusters at the MP2 and CCSD(T) levels of theory: Application to (H2O)m, m=2-6, 8, 11, 16 and 17." Journal of Chemical Physics 142, no. 23:234303. PNNL-SA-107534. doi:10.1063/1.4922262
  • Miliordos E., and S.S. Xantheas. 2015. "Ground and excited states of the [Fe(H2O)6]2+ and [Fe(H2O)6]3+ clusters: Insight into the electronic structure of the [Fe(H2O)6]2+ - [Fe(H2O)6]3+ complex." Journal of Chemical Theory and Computation 11, no. 4:1549-1563. PNNL-SA-107234. doi:10.1021/ct501143c
  • Miliordos E., and S.S. Xantheas. 2015. "On the validity of the basis set superposition error and complete basis set limit extrapolations for the binding energy of the formic acid dimer." Journal of Chemical Physics 142, no. 9:094311. PNNL-SA-107407. doi:10.1063/1.4913766
  • Werhahn J.C., E. Miliordos, and S.S. Xantheas. 2015. "A new variation of the Buckingham exponential-6 potential with a tunable, singularity-free short-range repulsion and an adjustable long-range attraction." Chemical Physics Letters 619. PNNL-SA-104855. doi:10.1016/j.cplett.2014.11.051


  • Miliordos E., and S.S. Xantheas. 2014. "Elucidating the mechanism behind the stabilization of multi-charged metal cations in water: A case study of the electronic states of microhydrated Mg2+, Ca2+ and Al3+”." Physical Chemistry Chemical Physics. PCCP 16, no. 15:6886-6892. PNNL-SA-96264. doi:10.1039/C3CP53636J
  • Miliordos E., and S.S. Xantheas. 2014. "On the bonding nature of ozone (O3) and its sulfur-substituted analogues SO2, OS2 and S3: Correlation between their biradical character and molecular properties." Journal of the American Chemical Society 136, no. 7:2808-2817. PNNL-SA-98997. doi:10.1021/ja410726u
  • Miliordos E., and S.S. Xantheas. 2014. "Unimolecular and hydrolysis channels for the detachment of water from microsolvated alkaline earth dication (Mg2+, Ca2+, Sr2+, Ba2+) clusters." Theoretical Chemistry Accounts 133, no. 4:Article No. 1450. PNNL-SA-99200. doi:10.1007/s00214-014-1450-4
  • Miliordos E., E. Apra, and S.S. Xantheas. 2014. "Benchmark Theoretical Study of the p-p Binding Energy in the Benzene Dimer." Journal of Physical Chemistry A 118, no. 35:7568-7578. PNNL-SA-101408. doi:10.1021/jp5024235
  • Pradzynski C.C., C.W. Dierking, F. Zurheide, R.M. Forck, U. Buck, T. Zeuch, and S.S. Xantheas. 2014. "Infrared detection of (H2O)20 isomers of exceptional stability: a drop-like and a face-sharing pentagonal prism cluster." Physical Chemistry Chemical Physics. PCCP16, no. 48:26691-26696. PNNL-SA-102598. doi:10.1039/c4cp03642e
  • Sahu N., S.R. Gadre, P. Bandyopadhyay, E. Miliordos, and S.S. Xantheas. 2014. "Low energy isomers of (H2O)25 from a hierarchical method based on Monte Carlo Temperature Basin Paving and Molecular Tailoring Approaches benchmarked by full MP2 calculations." Journal of Chemical Physics 141, no. 16:164304. PNNL-SA-102440. doi:10.1063/1.4897535
  • Vasdekis A.E., M.J. Wilkins, J.W. Grate, R.T. Kelly, A. Konopka, S.S. Xantheas, and M.T. Chang. 2014. "Solvent Immersion Imprint Lithography." Lab on a Chip 14, no. 12:2072-2080. PNNL-SA-95141. doi:10.1039/C4LC00226A
  • Werhahn J.C., D. Akase, and S.S. Xantheas. 2014. "Universal scaling of potential energy functions describing intermolecular interactions. II. The halide-water and alkali metal-water interactions." Journal of Chemical Physics 141, no. 6:064118. PNNL-SA-78240. doi:10.1063/1.4891820
  • Xantheas S.S., and J.C. Werhahn. 2014. "Universal scaling of potential energy functions describing intermolecular interactions. I. Foundations and scalable forms of new generalized Mie, Lennard-Jones, Morse, and Buckingham exponential-6 potentials." Journal of Chemical Physics 141, no. 6:064117. PNNL-SA-78241. doi:10.1063/1.4891819
  • Yoshida T., W.A. Farone, and S.S. Xantheas. 2014. "Isomers and conformational barriers of gas phase nicotine, nornicotine and their protonated forms." Journal of Physical Chemistry B118, no. 28:8273-8285. PNNL-SA-95198. doi:10.1021/jp501646p


  • Doi K., E. Togano, S.S. Xantheas, R. Nakanishi, T. Nagata, T. Ebata, and Y. Inokuchi. 2013. "Microhydration Effects on the Intermediates of the SN2 Reacation of Iodide Anion with Methyl Iodine." Angewandte Chemie International Edition 52, no. 16:4380-4383. PNNL-SA-91095. doi:10.1002/anie.201207697
  • Imoto S., S.S. Xantheas, and S. Saito. 2013. "Molecular origin of the difference in the HOH bend of the IR spectra between liquid water and ice." Journal of Chemical Physics 138, no. 5:054506-1/8. PNNL-SA-92117. doi:10.1063/1.4789951
  • Iwata S., P. Bandyopadhyay, and S.S. Xantheas. 2013. "Cooperative Roles of Charge Transfer and Dispersion Terms in Hydrogen-Bonded Networks of (H2O)n, n = 6, 11, and 16." Journal of Physical Chemistry A 117, no. 30:6641-6651. PNNL-SA-95025. doi:10.1021/jp403837z
  • Mardirossian N., D.S. Lambrecht, L. McCaslin, S.S. Xantheas, and M.P. Head-Gordon. 2013. "The Performance of Density Functionals for Sulfate-Water Clusters." Journal of Chemical Theory and Computation 9, no. 3:1368-1380. PNNL-SA-91097. doi:10.1021/ct4000235
  • Miliordos E., and S.S. Xantheas. 2013. "Efficient procedure for the numerical calculation of harmonic vibrational frequencies based on internal coordinates." Journal of Physical Chemistry A 117, no. 32:7019-7029. PNNL-SA-92774. doi:10.1021/jp3127576
  • Miliordos E., E. Apra, and S.S. Xantheas. 2013. "Optimal geometries and harmonic vibrational frequencies of the global minima of water clusters (H2O)n, n=2-6, and several hexamer local minima at the CCSD(T) level of theory." Journal of Chemical Physics 139, no. 11:114302-13. PNNL-SA-97024. doi:10.1063/1.4820448
  • Miliordos E., K. Ruedenberg, and S.S. Xantheas. 2013. "Unusual Inorganic Biradicals: A Theoretical Analysis." Angewandte Chemie International Edition 52, no. 22:5736-5739. PNNL-SA-92775. doi:10.1002/anie.201300654


  • He X., O. Sode, S.S. Xantheas, and S. Hirata. 2012. "Second-order many-body perturbation study of ice Ih." Journal of Chemical Physics 137, no. 20:204505-8. PNNL-SA-89304.
  • Hou G., H. Wen, K.A. Lopata, W. Zheng, K. Kowalski, N. Govind, and X.B. Wang, et al. 2012. "A Combined Gas-Phase Photoelectron Spectroscopic and Theoretical Study of Zeise's Anion and Its Bromine and Iodine Analogues." Angewandte Chemie International Edition 51, no. 26:6356-6360. PNNL-SA-86382. doi:10.1002/anie.201201959
  • Lambrecht D.S., L. McCaslin, S.S. Xantheas, E. Epifanovsky, and M.P. Head-Gordon. 2012. "Refined Energetic Ordering for Sulfate-Water (n=3-6) Clusters Using High-Level Electronic Structure Calculations." Molecular Physics 110, no. 19-20:2513-2521. PNNL-SA-88782. doi:10.1080/00268976.2012.708442
  • Sams R.L., S.S. Xantheas, and T.A. Blake. 2012. "Vapor Phase Infrared Spectroscopy and Ab Initio Fundamental Anharmonic Frequencies of Ammonia Borane." Journal of Physical Chemistry A 116, no. 12:3124-3136. PNNL-SA-84352. doi:10.1021/jp2115753
  • Xantheas S.S. 2012. "Low-Lying Energy Isomers and Global Minima of Aqueous Nanoclusters: Structures and Spectroscopic Features of the Pentagonal Dodecahedron (H2O)20 and (H3O)+(H2O)20." Canadian Journal of Chemical Engineering 90, no. 4:843-851. PNNL-SA-62086. doi:10.1002/cjce.21645
  • Yoo S., and S.S. Xantheas. 2012. "Enhancement of Hydrogen Storage Capacity in Hydrate Lattices." Chemical Physics Letters 525-526. PNNL-SA-83751. doi:10.1016/j.cplett.2011.12.036
  • Yoo S., and S.S. Xantheas. 2012. "Structures, Energetics and Spectroscopic Fingerprints of Water Clusters n = 2-24." In Handbook of Computational Chemistry, edited by J. Leszczynski. 761-792. New York, New York:Springer. PNNL-SA-71508.


  • Kaneko S., Y. Inokuchi, T. Ebata, E. Apra, and S.S. Xantheas. 2011. "Laser Spectroscopic and Theoretical Studies of Encapsulation Complexes of Calix[4]arene." Journal of Physical Chemistry A 115, no. 40:10846-10853. PNNL-SA-80093. doi:10.1021/jp204577j
  • Liu J., W.H. Miller, G.S. Fanourgakis, S.S. Xantheas, S. Imoto, and S. Saito. 2011. "Insights in Quantum Dynamical Effects in the Infrared Spectroscopy of Liquid Water from a Semiclassical Study with an ab Initio-Based Flexible and Polarizable Force Field." Journal of Chemical Physics 135, no. 24:244503. PNNL-SA-82605. doi:10.1063/1.3670960
  • Wang X.B., and S.S. Xantheas. 2011. "Photodetachment of Isolated Bicarbonate Anion: Electron Binding Energy of HCO3-." The Journal of Physical Chemistry Letters 2, no. 10:1204-1210. PNNL-SA-78502. doi:10.1021/jz200327f
  • Werhahn J.C., S. Pandelov, S. Yoo, S.S. Xantheas, and H. Iglev. 2011. "Dynamics of Confined Water Molecules in Aqueous Salt Hydrates." In Ultrafast Phenomena XVII: Proceedings of the 17th International Conference, July 18-23, 2010, Snowmass, CO, edited by M Chergui, D Jonas, E Riedle, RW Schoenlein and AJ Taylor, 463-465. Oxford:Oxford University Press. PNNL-SA-74390.
  • Werhahn J.C., S. Pandelov, S.S. Xantheas, and H. Iglev. 2011. "Dynamics of Weak, Bifurcated and Strong Hydrogen Bonds in Lithium Nitrate Trihydrate." The Journal of Physical Chemistry Letters 2, no. 13:1633-1638. PNNL-SA-79797. doi:10.1021/jz200591v
  • Whiteside A., S.S. Xantheas, and M.S. Gutowski. 2011. "Is Electronegativity a Useful Descriptor for the "Pseudo-Alkali-Metal" NH4?." Chemistry - A European Journal 17, no. 47:13105. PNNL-SA-80733. doi:10.1002/chem.201190241
  • Yoo S., and S.S. Xantheas. 2011. "Communication: The Effect of Dispersion Corrections on the Melting Temperature of Liquid Water." Journal of Chemical Physics 134, no. 12:Article No. 121105. PNNL-SA-77061. doi:10.1063/1.3573375
  • Yoo S., and S.S. Xantheas. 2011. "The role of hydrophobic surfaces in altering water mediated peptide-petide interactions in an aqueous environment." Journal of Physical Chemistry A 115, no. 23:6088-6092. PNNL-SA-67174. doi:10.1021/jp1107137


  • Bakalbassis E.G., E. Malamidou-Xenikaki, S. Spyroudis, and S.S. Xantheas. 2010. "Dimerization of Indanedioneketene to Spiro-oextanone: A Theoretical Study." Journal of Organic Chemistry 75, no. 16:5499-5504. PNNL-SA-72271. doi:10.1021/jo100500u
  • Ebata T., N. Hontama, Y. Inokuchi, T. Haino, E. Apra, and S.S. Xantheas. 2010. "Encapsulation of Arn complexes by Calix[4]arene: Endo- vs. exo-complexes." Physical Chemistry Chemical Physics. PCCP 12, no. 18:4569-4579. PNNL-SA-70965. doi:10.1039/b927441c
  • Glezakou V.A., S.T. Elbert, S.S. Xantheas, and K. Ruedenberg. 2010. "Analysis of Bonding Patterns in the Valence Isoelectronic series O-3, S-3, SO2 and OS2 in Terms of Oriented Quasi-Atomic Molecular Orbitals." Journal of Physical Chemistry A 114, no. 33:8923-8931. PNNL-SA-73193.
  • Hontama N., Y. Inokuchi, T. Ebata, C. Dedonder-Lardeau, C. Jouvet, and S.S. Xantheas. 2010. "The structure of the Calix[4]arene-(H2O) Cluster: The World’s Smallest Cup of Water." Journal of Physical Chemistry A 114, no. 9:2967-2972. PNNL-SA-67484.
  • Kusaka R., Y. Inokuchi, S.S. Xantheas, and T. Ebata. 2010. "Structures and Encapsulation Motifs of Functional Molecules probed by Laser Spectroscopic and Theoretical methods." Sensors 10, no. 4:3519-3548. PNNL-SA-70608. doi:10.3390/s100403519
  • Paesani F., S. Yoo, H.J. Bakker, and S.S. Xantheas. 2010. "Nuclear Quantum Effects in the Reorientation of Water." The Journal of Physical Chemistry Letters 1, no. 15:2316-2321. PNNL-SA-73194. doi:10.1021/jz100734w
  • Pandelov S., J.C. Werhahn, B.M. Pilles, S.S. Xantheas, and H. Iglev. 2010. "An empirical correlation between the enthalpy of solution of aqueous salts and their ability to form hydrates." Journal of Physical Chemistry A 114, no. 38:10454-10457. PNNL-SA-73993. doi:10.1021/jp106050r
  • Wang X.B., K. Kowalski, L.S. Wang, and S.S. Xantheas. 2010. "Stepwise hydration of the cyanide anion: A temperature-controlled photoelectron spectroscopy and ab initio computational study of CN-(H2O)n(n=2-5)." Journal of Chemical Physics 132, no. 12:124306/1-10. PNNL-SA-69676. doi:10.1063/1.3360306
  • Xantheas S.S., and M.S. Gordon. 2010. "A Tribute to Klaus Ruedenberg." Journal of Physical Chemistry 114, no. 33:8489. PNNL-SA-73669.
  • Yoo S., E. Apra, X. Zeng, and S.S. Xantheas. 2010. "High-Level ab initio electronic structure calculations of Water Clusters (H2O)16 and (H2O)17: a new global minimum for (H2O)16." The Journal of Physical Chemistry Letters 1, no. 20:3122-3127. PNNL-SA-74857. doi:10.1021/jz101245s


  • Apra E., A.P. Rendell, R.J. Harrison, V. Tipparaju, W.A. De Jong, and S.S. Xantheas. 2009. "Liquid Water: Obtaining the right answer for the right reasons." In Proceedings of the Conference on High Performance Computing Networking, Storage and Analysis (SC '09), November 14-20, 2009, Portland, Oregon. New York, New York:Association for Computing Machinery. PNNL-SA-65879. doi:10.1145/1654059.1654127
  • Hammond J.R., N. Govind, K. Kowalski, J. Autschbach, and S.S. Xantheas. 2009. "Accurate dipole polarizabilities for water clusters n=2-12 at the coupled-cluster level of theory and benchmarking of various density functionals." Journal of Chemical Physics 131, no. 21:Article Number:214103. PNNL-SA-67697.
  • Paesani F., F. Paesani, S.S. Xantheas, and G.A. Voth. 2009. "Infrared Spectroscopy and Hydrogen-Bond Dynamics of Liquid Water from Centroid Molecular Dynamics with an Ab Initio-Based Force Field." Journal of Physical Chemistry B 113, no. 39:13118-13130. PNNL-SA-68059.
  • Sun X., S. Yoo, S.S. Xantheas, and L.X. Dang. 2009. "The Reorientation Mechanism of Hydroxide Ions in Water: A Molecular Dynamics Study." Chemical Physics Letters 481, no. 1-3:9-16. PNNL-SA-66090.
  • Wang X.B., J.C. Werhahn, L.S. Wang, K. Kowalski, A. Laubereau, and S.S. Xantheas. 2009. "Observation of a remarkable temperature effect in the hydrogen bonding structure and dynamics of the CN-(H2O) cluster." Journal of Physical Chemistry A 113, no. 35:9579-9584. PNNL-SA-67173.
  • Wick C.D., and S.S. Xantheas. 2009. "Computational Investigation of the First Solvation Shell Structure of Interfacial and Bulk Aqueous Chloride and Iodide Ions." Journal of Physical Chemistry B 113, no. 13:4141-4146. PNNL-SA-62229. doi:10.1021/jp806782r
  • Xantheas S.S. 2009. "COMPUTATIONAL CHEMISTRY Dances with hydrogen cations." Nature 457, no. 7230:673-674. PNNL-SA-64321.
  • Xantheas S.S., and G.A. Voth. 2009. "Aqueous Solutions and their Interfaces." Journal of Physical Chemistry B 113, no. 13:3997-3999. PNNL-SA-64113.
  • Yoo S., M.V. Kirov, and S.S. Xantheas. 2009. "Low-energy networks of the T-cage (H2O)(24) cluster and their use in constructing periodic unit cells of the structure I (sl) hydrate lattice." Journal of the American Chemical Society 131, no. 22:7564-7566. PNNL-SA-64701.
  • Yoo S., S.S. Xantheas, and X.C. Zeng. 2009. "The Melting Temperature of Bulk Silicon from ab initio Molecular Dynamics Simulations." Chemical Physics Letters 481, no. 1-3:88-90. PNNL-SA-67809.
  • Yoo S., X. Zeng, and S.S. Xantheas. 2009. "On the phase diagram of water with density functional theory potentials: the melting temperature of Ice I-h with the Perdew-Burke-Ernzerhof and Becke-Lee-Yang-Parr functionals." Journal of Chemical Physics 130, no. 22:Art. No. 211102. PNNL-SA-65865.


  • Fanourgakis G.S., and S.S. Xantheas. 2008. "Development of transferable interaction potentials for water: V. Extension of the flexible, polarizable, Thole-Type Model potential (TTM3-F, v. 3.0) to describe the vibrational spectra of water clusters and liquid water." Journal of Chemical Physics 128, no. 7:Art. No. 074506. PNNL-SA-58189.
  • Kathmann S.M., G.K. Schenter, and S.S. Xantheas. 2008. "On the Determination of Monomer Dissociation Energies of Small Water Clusters from Photoionization Experiments." Journal of Physical Chemistry A 112, no. 9:1851-1853. PNNL-SA-58088. doi:10.1021/jp710624r
  • Kirov M.V., G.S. Fanourgakis, and S.S. Xantheas. 2008. "Identifying the Most Stable Networks in Polyhedral Water Clusters." Chemical Physics Letters 461, no. 4-6:180-188. PNNL-SA-44405. doi:10.1016/j.cplett.2008.04.079
  • Lipciuc M.L., F. Wang, X. Yang, T.N. Kitsopoulos, G.S. Fanourgakis, and S.S. Xantheas. 2008. "Cluster-controlled Photofragmentation: The Case of the Xe-Pyrrole Cluster." ChemPhysChem9, no. 13:1838-1841. PNNL-SA-59269. doi:10.1002/cphc.200800288


  • Blake T.A., E.D. Glendening, R.L. Sams, S.W. Sharpe, and S.S. Xantheas. 2007. "High Resolution Infrared Spectroscopy in the 1200--1300 cm-1 Region and Accurate Theoretical Estimates for the Structure and Ring-Puckering Barrier of Perfluorocyclobutane." Journal of Physical Chemistry A 111, no. 44:11328-11341. PNNL-SA-54711. doi:10.1021/jp072521f
  • Fanourgakis G.S., V. Tipparaju, J. Nieplocha, and S.S. Xantheas. 2007. "An efficient parallelization scheme for molecular dynamics simulations with many-body, flexible, polarizable empirical potentials: Application to water." Theoretical Chemistry Accounts 117, no. 1:73-84. PNNL-SA-46786.
  • Pankewitz T., A. Lagutschenkov, G. Niedner-schatteburg, S.S. Xantheas, and Y. Lee. 2007. "Infrared spectrum of NH4+(H2O): Evidence for mode specific fragmentation." Journal of Chemical Physics 126, no. 7:Art. No. 074307. PNNL-SA-52932.
  • Rubio-Lago L., D. Zaouris, Y. Sakellariou, D. Sofikitis, T.N. Kitsopoulos, F. Wang, and X. Yang, et al. 2007. "Photofragment slice imaging studies of pyrrole and the Xe...pyrrole cluster." Journal of Chemical Physics 127, no. 6:064306 (12 pages). PNNL-SA-54083.
  • Slipchenko M.N., B.G. Sartakov, A.F. Vilesov, and S.S. Xantheas. 2007. "Study of NH stretching vibrations in small ammonia clusters by infrared spectroscopy in He droplets and ab initio calculations." Journal of Physical Chemistry A 111, no. 31:7460-7471. PNNL-SA-53939. doi:10.1021/jp071279+


  • Bulusu S., S. Yoo, E. Apra, S.S. Xantheas, and X. Zeng. 2006. "Lowest-energy structures of water clusters (H2O)(11) and (H2O)(13)." Journal of Physical Chemistry A 110, no. 42:11781-11784. PNNL-SA-50699.
  • Fanourgakis G.S., and S.S. Xantheas. 2006. "The bend angle of water in ice Ih and liquid water: The significance of implementing the nonlinear monomer Dipole Moment Surface in classical interaction potentials." Journal of Chemical Physics 124, no. 17:Art. no. 174504. PNNL-SA-48164.
  • Fanourgakis G.S., and S.S. Xantheas. 2006. "The flexible, polarizable, thole-type interaction potential for water (TTM2-F) Revisited." Journal of Physical Chemistry A 110, no. 11:4100-4106. PNNL-SA-43998. doi:10.1021/jp056477k
  • Fanourgakis G.S., G.K. Schenter, and S.S. Xantheas. 2006. "A quantitative account of quantum effects in liquid water." Journal of Chemical Physics 125, no. 14:Art. No. 141102. PNNL-SA-48955.
  • Feller D.F., D.A. Dixon, T.H. Dunning, M. Dupuis, D. McClemore, K.A. Peterson, and S.S. Xantheas, et al. 2006. Computational Thermochemistry and Benchmarking of Reliable Methods. PNNL-15863. Richland, WA: Pacific Northwest National Laboratory.
  • Francisco J.S., S.M. Kathmann, G.K. Schenter, L.X. Dang, S.S. Xantheas, B.C. Garrett, and S. Du, et al. 2006. A Computational Approach to Understanding Aerosol Formation and Oxidant Chemistry in the Troposphere. PNNL-15772. Richland, WA: Pacific Northwest National Laboratory.
  • Ramazan K.A., L.M. Wingen, Y. Miller, G.M. Chaban, R.B. Gerber, S.S. Xantheas, and B.J. Finlayson-Pitts. 2006. "New Experimental and Theoretical Approach to the Heterogeneous Hydrolysis of NO2: Key Role of Molecular Nitric Acid and Its Complexes." Journal of Physical Chemistry A 110, no. 21:6886-6897. PNNL-SA-47338. doi:10.1021/jp056426n
  • Xantheas S.S. 2006. "Anharmonic vibrational spectra of hydrogen bonded clusters: Comparison between higher energy derivative and mean-field grid based methods." International Reviews in Physical Chemistry 25, no. 4:719-733. PNNL-SA-50327.
  • Xantheas S.S. 2006. "Interaction potentials for water from accurate cluster calculations." In Intermolecular Forces and Clusters II, Structure and Bonding, edited by D Wales. 119-148. Berlin:Springer-Verlag. PNNL-SA-45721.
  • Xantheas S.S., and T.A. Blake. 2006. "Structure, Vibrational Spectra and Ring Puckering Barrier of Cyclobutane." Journal of Physical Chemistry A 110. PNNL-SA-36478. doi:10.1021/jp062472r


  • Fanourgakis G.S., E. Apra, W.A. De Jong, and S.S. Xantheas. 2005. "High-level ab-initio calculations for the four low-lying families of minima of (H2O)20: II. Spectroscopic signatures of the dodecahedron, fused cubes, face-sharing pentagonal prisms, and edge-sharing pentagonal prisms hydrogen bonding networks." Journal of Chemical Physics 122, no. 13:134304. PNNL-SA-43774.
  • Garrett B.C., D.A. Dixon, D.M. Camaioni, D.M. Chipman, M.A. Johnson, C.D. Jonah, and G.A. Kimmel, et al. 2005. "Role of Water in Electron-Initiated Processes and Radical Chemistry: Issues and Scientific Advances." Chemical Reviews 105, no. 1:355-389. PNNL-SA-42304. doi:10.1021/cr030453x
  • Hirata S., M. Valiev, M. Dupuis, S.S. Xantheas, S. Sugiki, and H. Sekino. 2005. "Fast Electron Correlation Methods for Molecular Clusters in the Ground and Excited States." Molecular Physics 103, no. 15-16:2255-2265. PNNL-SA-42030.
  • Lagutschenkov A., G.S. Fanourgakis, G. Niedner-Schateburg, and S.S. Xantheas. 2005. "The spectroscopic signature of the “all-surface” to “internally solvated” structural transition in water clusters in the n=17-21 size regime." Journal of Chemical Physics 122, no. 19:194310-1 - 194310-9. PNNL-SA-44122. doi:10.1063/1.1899583
  • Xantheas S.S., W. Roth, and I. Fischer. 2005. "Competition between van der Waals and Hydrogen Bonding interactions: Structure of the trans-1-Naphthol/N2 cluster." Journal of Physical Chemistry A 109, no. 42:9584-9589. PNNL-SA-45664.


  • Bowman J.M., and S.S. Xantheas. 2004. "‘Morphing’ of ab initio-based interaction potentials to spectroscopic accuracy: Application to Cl-(H2O)." Pure and Applied Chemistry 76, no. 1:29-35. PNNL-SA-38947.
  • Burnham C.J., and S.S. Xantheas. 2004. "On the Importance of Zero-Point Effects in Molecular Level Classical Simulations of Water." Journal of Molecular Liquids 110, no. 1-3:177-192. PNNL-SA-32663.
  • Fanourgakis G.S., E. Apra, and S.S. Xantheas. 2004. "High-level ab initio calculations for the four low-lying families of minima of (H2O)(20): 1. Estimates of MP2/CBS binding energies and comparison with empirical potentials." Journal of Chemical Physics 121, no. 6:2655-2663. PNNL-SA-41351.
  • Xantheas S.S. 2004. "Intermolecular Interactions and Cooperative Effects from Electronic Structure Calculations: An Effective Means for Developing Interaction Potentials for Condensed Phase Simulations." In Novel Approaches to the Structure and Dynamics of Liquids: Experiments, Theories and Simulations: Proceedings of the NATO Advanced Study Institute, September 6-15, 2002, Rhodes, Greece, edited by J Samios and VA Durov. 1-15. Dordrecht:Springer. PNNL-SA-43747.
  • Xantheas S.S., and E. Apra. 2004. "The Binding Energies of the D2d and S4 Water Octamer Isomers: High-level Electronic Structure and Empirical Potential Results." Journal of Chemical Physics 120, no. 2:823-828. PNNL-SA-39513.


  • Chaban G.M., S.S. Xantheas, and R.B. Gerber. 2003. "Anharmonic Vibrational Spectroscopy of the F-(H2O)n complexes, n=1, 2." Journal of Physical Chemistry A 107, no. 24:4952-4956. PNNL-SA-38113.


  • Burnham C.J., and S.S. Xantheas. 2002. "01/22/2002Development of Transferable Interaction Models for Water: III. Reparameterization of an All-Atom Polarizable Rigid Model (TTM2-R) from First Principles." Journal of Chemical Physics 116, no. 4:1500-1510. PNNL-SA-34387.
  • Burnham C.J., and S.S. Xantheas. 2002. "Development of Transferable Interaction Models for Water: I. Prominent Features of the Water Dimer Potential Energy Surface." Journal of Chemical Physics 116, no. 4:1479-1492. PNNL-SA-34922.
  • Burnham C.J., S.S. Xantheas, M. Miller, B.E. Applegate, and R. Miller. 2002. "The Formation of Cyclic Water Complexes by Sequential Ring Insertion: Experiment and Theory." Journal of Chemical Physics 117, no. 3:1109-1122. PNNL-SA-35827.
  • Dunning T.H., R.J. Harrison, D.F. Feller, and S.S. Xantheas. 2002. "Promise and Challenge of High-performance Computing, with Examples from Molecular Modeling." Philosophical Transactions. Mathematical, Physical & Engineering Sciences 360, no. 1795:1079-1105. PNNL-SA-35597.
  • Garrett B.C., R. Bianco, L.X. Dang, D.A. Dixon, M. Dupuis, J. Francisco, and B. Gertner, et al. 2002. A Computational Approach to Understanding Oxidant Chemistry and Aerosol Formation in the Troposphere. PNNL-14009. Richland, WA: Pacific Northwest National Laboratory.
  • Mccurdy P.R., W.P. Hess, and S.S. Xantheas. 2002. "Nitric acid-water complexes: Theoretical calculations and comparison to experiment." Journal of Physical Chemistry 106, no. 33:7628-7635. PNNL-SA-35804.
  • Xantheas S.S., C.J. Burnham, and R.J. Harrison. 2002. "Development of Transferable Interaction Models for Water: II. Accurate Energetics of the First Few Water Clusters from First Principles." Journal of Chemical Physics 116, no. 4:1493-1499. PNNL-SA-34386.


  • Burnham C.J., and S.S. Xantheas. 2001. "Development of Transferable Interaction Models for Water: IV. A Flexible, All-atom Polarizable Potential (TTM2-F) based on Geometry Dependent Charges derived from an Ab Initio Monomer Dipole Moment Surface." Journal of Chemical Physics 116, no. 12:5115-5124. PNNL-SA-34728.
  • Tzeli D., A. Mavridis, and S.S. Xantheas. 2001. "A Molecular Level Study of the Aqueous Microsolvation of Acetylene." Chemical Physics Letters 340. PNNL-SA-33399.


  • Batista E.R., S.S. Xantheas, and H. Jonsson. 2000. "Electric Fields in Ice and Near Water Clusters." Journal of Chemical Physics 112, no. 7:3285-3292. PNNL-SA-30702.
  • Blake T.A., S.W. Sharpe, and S.S. Xantheas. 2000. "Rotationally Resolved Spectroscopy of a Librational Fundamental Band of Hydrogen Fluoride Tetramer." Journal of Chemical Physics113, no. 2:707-718. PNNL-SA-32713.
  • Tzeli D., A. Mavridis, and S.S. Xantheas. 2000. "A First Principles Study of the Acetylene - Water Interaction." Journal of Chemical Physics 112, no. 14:6178-6189. PNNL-SA-31354.
  • Xantheas S.S. 2000. "Cooperativity and Hydrogen Bonding Network in Water Clusters." Chemical Physics 258, no. 2-3:225-231. PNNL-SA-29343.


  • Ayotte P., S.B. Nielsen, G.H. Weddle, M.A. Johnson, and S.S. Xantheas. 1999. "Spectroscopic observation of ion-induced water dimer dissociation in the X-(H2O)2 (X=F, Cl, Br, I) clusters." Journal of Physical Chemistry A 103, no. 50:10665-10669. PNNL-SA-31405.
  • Batista E.R., S.S. Xantheas, and H. Jonsson. 1999. "Multipole Moments of Water Molecules in Clusters and Ice Ih from First Principles Calculations." Journal of Chemical Physics 111, no. 13:6011-6015. PNNL-SA-30705.
  • Burnham C.J., J. Li, J. Li, S.S. Xantheas, M. Leslie, and M. Leslie. 1999. "The Parametrization of a Thole-type All-Atom Polarizable Water Model from First Principles and its Application to the Study of Water Clusters (n=2-21) and the Phonon Spectrum on ice Ih." Journal of Chemical Physics 110, no. 9:4566-4581. PNNL-SA-30384.
  • Cabarcos O.M., C.J. Wienheimer, J. Lisy, and S.S. Xantheas. 1999. "Microscopic Hydration of the Fluoride Anion." Journal of Chemical Physics 110, no. 1:5-8. PNNL-SA-30200.
  • Dorsett H.E., R.O. Watts, and S.S. Xantheas. 1999. "Probing Temperature Effects on the Hydrogen Bonding Network of the CI-(H2O)(2) Cluster." Journal of Physical Chemistry A 103, no. 18:3351-3355. PNNL-SA-12035.
  • Fanourgakis G.S., S.C. Farantos, C.H. Luder, M. Velegrakis, and S.S. Xantheas. 1999. "Photofragmentation Spectra and Potential Energy Surfaces of Sr+Ar2." Physical Chemistry Chemical Physics. PCCP 1, no. 6:977-981. PNNL-SA-30495.
  • Weis P., P. Weis, P. Kemper, P. Kemper, M.T. Bowers, and S.S. Xantheas. 1999. "A New Determination of the Fluoride Ion-Water Bond Energy." Journal of the American Chemical Society 121, no. 14:3531-3532. PNNL-SA-30353.


  • Mavridis A., A. Kalemos, and S.S. Xantheas. 1998. "Theoretical Investigation of the Ground X3 Sigma(-) State of Nitrogen Bromide." Journal of Physical Chemistry A 102, no. 51:10536-10539. PNNL-SA-30210.