About

Professor Erik Santiso leads a research group focused on developing and applying molecular simulations and data-driven methods to understand and control the assembly, transformation, and function of complex molecular materials across various time and length scales. His work involves designing computational tools that accelerate the discovery and optimization of advanced materials and formulations, effectively bridging fundamental molecular science with practical applications in fields such as pharmaceuticals, energy, and sustainability. The group combines molecular dynamics, enhanced sampling, and rare-event methods with machine learning techniques to investigate the structure, dynamics, and phase behavior of molecular and soft-matter systems. A central theme of his research is the prediction and control of nucleation, crystallization, and amorphous structures to enable the development of better-performing materials, particularly in drug products, functional polymers, and catalytic and interfacial systems. Professor Santiso's group collaborates closely with experimental researchers, using simulations to interpret experimental measurements and guide the design of new materials, processing routes, and formulations. This integrated approach facilitates the identification of molecular-level design rules that can be applied across different chemistries and application domains.

Research topics

• Artificial Intelligence
• Computer Science
• Physics
• Mathematics
• Thermodynamics
• Quantum mechanics
• Data science
• Engineering
• Materials science
• Geometry
• Mechanics
• Chemistry
• Statistical physics
• Mathematical analysis
• Biology
• Biochemical engineering
• Philosophy
• Classical mechanics
• Theoretical physics

Selected publications

• Quantum one-dimensional materials at low temperature: Pre-critical effects, long-range correlations, and specific heats

  The Journal of Chemical Physics · 2025-12-24 · 1 citations

  article

  In 1925, Ising showed that a one-dimensional (1D) system of particles that interact with short-range intermolecular forces cannot exhibit a phase transition at finite temperatures. However, he also found that the correlation length ξ diverges to infinity at T = 0 K and low density, the signature of a critical point. In this work, we report classical and quantum mechanical path integral Monte Carlo (PIMC) results for the static pair correlation function, the correlation length, and specific heats for a 1D system of spin 0 Lennard-Jones (LJ) molecules modeled on hydrogen, H2. Our PIMC results, which are for temperatures down to T* = kBT/ɛ = 0.01 and densities down to ρ* = ρσ = 0.1, exhibit strong long-range fluctuations out to 50 molecular diameters or more at low temperatures and low densities. In addition, the correlation length appears to diverge as the temperature approaches 0 K, thus strongly confirming Ising's prediction of a critical point at T = 0 K. Our classical Monte Carlo results, by contrast, show smaller values of the correlation length, since it does not capture the quantum dispersion effect. The specific heat at constant length is also found to diverge on lowering the temperature toward absolute zero, a further signature of the approach to a critical point, but the third law of thermodynamics requires that it drop to zero at a temperature that is below the lowest value studied in this work. The findings reported here are relevant to recent advances in the synthesis of one-dimensional van der Waals materials.

  PublisherDOI

• Quantum One-Dimensional Materials at Low Temperature: Pre-Critical Effects,Long-range Correlations and Specific Heats

  AIP Publishing · 2025-01-01

  otherOpen access

  In 1925 Ising showed that a one-dimensional (1D) system of particles that interact with short-range intermolecular forces cannot exhibit a phase transition at finite temperatures.However, he also found that the correlation length ξ diverges to infinity at T = 0 K and low density, the signature of a critical point. In this work, we report classical and quantum mechanical path integral Monte Carlo (PIMC) results for the static pair correlation function, the correlation length and specific heats for a 1D system of spin 0 Lennard-Jones (LJ) molecules modeled on hydrogen, H2. Our PIMC results, which are for temperatures down to T ∗ = kBT /ε = 0.01 and densities down to ρ∗ = ρσ = 0.1, exhibit strong long-range fluctuations, out to 50 molecular diameters or more at low temperatures and low densities. In addition, the correlation length appears to diverge as the temperature approaches 0 K, thus strongly confirming Ising's prediction of a critical point at T = 0 K. Our classical Monte Carlo results, by contrast, show smaller values of the correlation length, since it does not capture the quantum dispersion effect. The specific heat at constant length is also found to diverge on lowering the temperature towards absolute zero, a further signature of approach to a critical point, but the Third Law of Thermodynamics requires that it drop to zero at a temperature that is below the lowest value studied in this work. The findings reported here are relevant in recent advances in the synthesis of one-dimensional van der Waals materials.

  PublisherDOI

• Supplementary On line material

  AIP Publishing · 2025-12-24

  articleOpen access

  Supplementary information related to the virial and kinetic estimators, and results for higher densities

  PublisherDOI

• DESPASITO: A Python Package for SAFT EOS Parametrization and Thermodynamic Calculations

  The Journal of Open Source Software · 2025-02-07 · 3 citations

  articleOpen accessSenior author

  DESAPSITO is an open-source Python package that provides access to complex thermodynamic calculations, with a special interest in the statistical associating fluid theory (SAFT) equation of state.The modular design of DESPASITO provides an extensible architecture that could be easily customized or extended by other researchers.The currently supported equations of state (SAFT--Mie, SAFT--SW, and Peng-Robinson) thoroughly represent the dynamic use of this platform and its intentional design for expansion.This growth mindset extends into the other modules, as additional thermodynamic calculations and parameter fitting routines may be included.Nonetheless, the current state of DESPASITO can be employed by the simulation community for coarse-grained force field development with SAFT--Mie.The DESPASITO package is available from PyPI and its source code is hosted on GitHub, which provides a platform for community-driven contributions and feedback.

  PublisherOA PDFDOI

• Supplementary On line material

  AIP Publishing · 2025-12-24

  articleOpen accessSenior author

  Supplementary information related to the virial and kinetic estimators, and results for higher densities

  PublisherDOI

• Quantum One-Dimensional Materials at Low Temperature: Pre-Critical Effects,Long-range Correlations and Specific Heats

  AIP Publishing · 2025-01-01

  otherOpen access

  In 1925 Ising showed that a one-dimensional (1D) system of particles that interact with short-range intermolecular forces cannot exhibit a phase transition at finite temperatures.However, he also found that the correlation length ξ diverges to infinity at T = 0 K and low density, the signature of a critical point. In this work, we report classical and quantum mechanical path integral Monte Carlo (PIMC) results for the static pair correlation function, the correlation length and specific heats for a 1D system of spin 0 Lennard-Jones (LJ) molecules modeled on hydrogen, H2. Our PIMC results, which are for temperatures down to T ∗ = kBT /ε = 0.01 and densities down to ρ∗ = ρσ = 0.1, exhibit strong long-range fluctuations, out to 50 molecular diameters or more at low temperatures and low densities. In addition, the correlation length appears to diverge as the temperature approaches 0 K, thus strongly confirming Ising's prediction of a critical point at T = 0 K. Our classical Monte Carlo results, by contrast, show smaller values of the correlation length, since it does not capture the quantum dispersion effect. The specific heat at constant length is also found to diverge on lowering the temperature towards absolute zero, a further signature of approach to a critical point, but the Third Law of Thermodynamics requires that it drop to zero at a temperature that is below the lowest value studied in this work. The findings reported here are relevant in recent advances in the synthesis of one-dimensional van der Waals materials.

  PublisherDOI

• <i>In Silico</i> Structural Comparison of Aromatic and Aliphatic Chiral Peptoid Oligomers

  The Journal of Physical Chemistry B · 2024-11-04 · 2 citations

  articleSenior authorCorresponding

  Atomistic simulations of peptoids have the capability to predict structure–property relationships, depending on the accuracy of the associated force field. This work presents an addendum to the CGenFF-NTOID peptoid force field for aliphatic side chains. We develop parameters for two aliphatic side chains, RN1-tertiary butylethyl glycine (r1tbe) and SN1-tertiary butylethyl glycine (s1tbe). Enhanced sampled (well-tempered metadynamics) atomistic simulations are performed using CGenFF-NTOID to determine the monomer structural preferences for these side chains. The free energy minima attained through these simulations are compared with structural observations obtained from experiments. We also compare the structural preferences of aliphatic s1tbe and aromatic SN1-naphthylethyl glycine (s1ne). This is done through parallel bias metadynamics on monomers and pentamers of s1tbe and s1ne. The structural observations through simulations are also compared with available experimental metrics of the dihedral angles and pitch. The pentamer minima structures are also compared with ab initio optimized structures, which show excellent agreement. This comparison illustrates alternatives to aromatic side chains that can be used to stabilize peptoid secondary structures. The developed parameters help to increase the diversity of peptoid side chains available for materials discovery through computational studies.

  PublisherDOI

• Isothermal Titration Calorimetry Reveals Entropy-Driven Bisphenol A Epoxy Resin Adhesion to Metal Oxide Surfaces

  Macromolecules · 2024-01-31 · 12 citations

  article

  Polymer-coated metals are ubiquitous in multiple industries as a corrosion protection strategy. Particularly in food and beverage packaging, bisphenol A (BPA)-based epoxy coatings provide an excellent barrier and strong adhesion to metals. There is, however, a need to design safer, alternative coatings with similar adhesion as BPA-epoxies due to environmental and health concerns associated with BPA. Limited critical information exists on epoxy-metal interactions and the effect of interfacial functional group concentration on overall adhesion due to the constraints of most experimental methods, which typically probe the interface only within a few nanometers in situ. Herein, we use isothermal titration calorimetry (ITC) and molecular dynamics simulations to characterize the thermodynamics of epoxy-metal oxide binding in the liquid phase and identify the influence of epoxy resin structure and metal oxide surface chemistry in dictating the binding process. Across a series of epoxy resins and three metal oxides, we reveal a previously unreported dominant role of entropy in the binding process, primarily facilitated by the release of bound solvent molecules from the epoxy/metal interface with possible contributions from dispersive OH–π interactions between the benzene rings of the resin and the –OH groups on the metal oxide surface. Enthalpy-favored hydrogen bonding between the –OH groups of the resin and the metal oxide plays a supporting role in the binding, with its participation dependent on the interfacial –OH group concentration. ITC therefore offers key molecular insights into the relative functional group contributions to the adhesion mechanism and informs the rational design of next-generation polymer coatings.

  PublisherDOI

• Using Enhanced Sampling Simulations to Study the Conformational Space of Chiral Aromatic Peptoid Monomers

  Journal of Chemical Theory and Computation · 2023-11-08 · 6 citations

  articleSenior authorCorresponding

  Peptoids, or N-substituted glycines, are peptide-like materials that form a wide variety of secondary structures owing to their enhanced flexibility and a diverse collection of possible side chains. Compared to that of peptides, peptoids have a substantially more complex conformational landscape. This is mainly due to the ability of the peptoid amide bond to exist in both cis- and trans-conformations. This makes conventional molecular dynamics simulations and even some enhanced sampling approaches unable to sample the complete energy landscapes. In this article, we present an extension to the CGenFF-NTOID peptoid atomistic forcefield by adding parameters for four side chains to the previously available collection. We employ explicit solvent well-tempered metadynamics simulations to optimize our forcefield parameters and parallel bias metadynamics to study the cis–trans isomerism for SN1-phenylethyl (s1pe) and SN1-naphthylethyl (s1ne) peptoid monomers, the free energy minima generated from which are validated with available experimental data. In the absence of experimental data, we supported our atomistic simulations with ab initio calculations. This work represents an important step toward the computational design of peptoid-based materials.

  PublisherDOI

• An atomically smooth container: Can the native oxide promote supercooling of liquid gallium?

  iScience · 2023-03-23 · 33 citations

  articleOpen access

  Metals tend to supercool-that is, they freeze at temperatures below their melting points. In general, supercooling is less favorable when liquids are in contact with nucleation sites such as rough surfaces. Interestingly, bulk gallium (Ga) can significantly supercool, even when it is in contact with heterogeneous surfaces that could provide nucleation sites. We hypothesized that the native oxide on Ga provides an atomically smooth interface that prevents Ga from directly contacting surfaces, and thereby promotes supercooling. Although many metals form surface oxides, Ga is a convenient metal for studying supercooling because its melting point of 29.8°C is near room temperature. Using differential scanning calorimetry (DSC), we show that freezing of Ga with the oxide occurs at a lower temperature (-15.6 ± 3.5°C) than without the oxide (6.9 ± 2.0°C when the oxide is removed by HCl). We also demonstrate that the oxide enhances supercooling via macroscopic observations of freezing. These findings explain why Ga supercools and have implications for emerging applications of Ga that rely on it staying in the liquid state.

  PublisherOA PDFDOI

Recent grants

• CDS&E: Molecular Modeling of Solute Precipitate Nucleation

  NSF · $329k · 2019–2024

• Element:Software:Enabling Millisecond-Scale Biomolecular Dynamics

  NSF · $600k · 2018–2023

Frequent coauthors

• Marco Buongiorno Nardelli

  35 shared

• Keith E. Gubbins

  North Carolina State University

  34 shared

• Kaihang Shi

  University at Buffalo, State University of New York

  11 shared

• Bernhardt L. Trout

  9 shared

• A. M. George

  Norfolk State University

  8 shared

• Milen K. Kostov

  Norfolk State University

  8 shared

• Francisco R. Hung

  Northeastern University

  8 shared

• Stefano Menegatti

  North Carolina State University

  7 shared