About

Elif Ertekin is an Associate Professor, R. Andersen Faculty Scholar, and Director of Mechanics Programs at the Mechanical Science and Engineering Department at the University of Illinois at Urbana-Champaign. Her research focuses on using computation, modeling, and simulation to develop a microscopic understanding of atomic and electronic scale processes in materials, with applications in thermal transport, energy conversion, and defect chemistry in solid state materials. She has received numerous awards including the NSF CAREER Award, the TMS Early Career Faculty Fellow Award, the Emerging Leader Award from the Society of Women Engineers, the Dean's Award for Excellence in Research, and the Rose Award for Teaching Excellence at Illinois. Her research group is dedicated to understanding fundamental problems at the intersection of materials science, mechanics, and condensed matter physics, employing methods such as high-throughput computation, materials informatics, and inverse design to enable materials discovery, design, and optimization. She collaborates with experimental groups to enhance the predictive capabilities of computational models, particularly in areas like battery materials, thermoelectrics, solid oxide fuel and electrolysis cells, and wide band gap semiconductors for power electronics. Her academic positions include serving as Associate Head for Graduate Programs and Research since 2024 and as an Associate Professor since 2017.

Research topics

• Materials science
• Chemistry
• Nanotechnology
• Computer Science
• Physical chemistry
• Political Science
• Physics
• Optoelectronics
• Ecology
• Law
• Quantum mechanics
• Engineering physics
• Geometry
• Engineering
• Crystallography
• Chemical physics
• Condensed matter physics
• Environmental economics
• Combinatorics
• Thermodynamics
• Composite material
• Mathematics
• Mechanical engineering
• Chemical engineering

Selected publications

• From solid-state electrolytes to cathodes: tuning mixed ionic-electronic conductivity in sodium metal halides

  ChemRxiv · 2026-03-22

  articleOpen access

  Mixed ionic-electronic conductors (MIEC) are exciting options for battery materials, encompassing next generation cathodes and catholytes. Unfortunately, control over mixed transport parameters in sodium metal chloride MIECs has not been well explored. Herein we investigate the isostructural substitution series of NaAl 1−x Fe x Cl 4 to explore the transition from a single ion conductor to an MIEC. We observe an increase in electronic conductivity due to the inclusion of the Fe 3+ 3 d states, which is accompanied by a slight decrease in ionic conductivity in the metal site-mixed materials. To explore the electronic evolution, band calculations suggest that the addition of 3 d states lead to color and electronic changes in this material system, which is in agreement with optical absorption measurements. This work presents one pathway to tune the ionic and electronic transport of MIECs.

  PublisherOA PDFDOI

• Frontiers of defect, transport, and reaction theories in complex and driven solid-state ionic materials

  MRS Bulletin · 2026-05-08

  articleOpen access

  Abstract Advances in solid-state ionic materials theory, synthesis, characterization, and simulation over the past century have enabled development of quantitative frameworks and descriptors to describe defect populations, transport, and interfacial reactions that approximate observable behavior in dilute, crystalline compositions near equilibrium. Increasing development of nondilute, disordered, or extended-defect-laden materials, and new operating conditions further from equilibrium, particularly in emerging energy, manufacturing, and information contexts, motivate development of new theoretical frameworks. This article provides an overview of computational and experimental advances in understanding defect-mediated behavior in ionic materials for batteries, fuel/electrolysis cells, sensors, thermochemical reactors, artificial synapses, ionic nanomanufacturing, and related technologies. Topics include: (1) point defects in nondilute and complex solid-solution systems, (2) point-defect populations and transport in and near extended defects, (3) defect equilibria and mobility in the excited state, (4) developing theories for ionic transport, including high-field effects and dynamic descriptors, and (5) emerging descriptors for surface reaction kinetics at intermediate-high temperatures. Graphical Abstract

  PublisherDOI

• SLayerGen: a Crystal Generative Model for all Space and Layer Groups

  arXiv (Cornell University) · 2026-05-07

  preprintOpen accessSenior author

  Crystal generative models have shown rapid progress for accelerating the discovery of bulk, periodic materials. However, many material systems such as 2D superconductors, thin film semiconductors, and catalytic surfaces are diperiodic, i.e., aperiodic along one of the lattice directions. These systems are invariant under the layer groups, which are known to influence materials properties yet not considered by existing models. In this paper, we propose SLayerGen, a generative model that produces crystals constrained to be invariant to any space or layer group. SLayerGen consists of coarse-to-fine discrete autoregressive lattice generation; transformer-based autoregressive sampling of Wyckoff positions, elements, and numbers of symmetrically unique atoms; and space or layer group equivariant diffusion of atomic coordinates. For the diffusion component, we corrected an inconsistency in the loss from prior work arising from hexagonal groups being non-orthogonal in fractional coordinates. To facilitate progress in generative modeling of diperiodic materials, we assembled and filtered datasets of monolayers and bilayers, propose relevant evaluation metrics, and developed novel representations for layer group symmetries. For de novo generation of diperiodic materials, SLayerGen achieves consistent performance gains over bulk crystal generative models and is competitive when training jointly on bulk and diperiodic materials.

  PublisherDOI

• Ultraviolet photoeffects on oxygen–hydrogen interstitial clusters in rutile TiO ₂

  Physical Chemistry Chemical Physics · 2026-01-01

  articleOpen access

  Ultraviolet illumination alters the concentrations of interstitial clusters containing oxygen and hydrogen in TiO 2 exposed to liquid water.

  PublisherOA PDFDOI

• SLayerGen: a Crystal Generative Model for all Space and Layer Groups

  ArXiv.org · 2026-05-07

  articleOpen accessSenior author

  Crystal generative models have shown rapid progress for accelerating the discovery of bulk, periodic materials. However, many material systems such as 2D superconductors, thin film semiconductors, and catalytic surfaces are diperiodic, i.e., aperiodic along one of the lattice directions. These systems are invariant under the layer groups, which are known to influence materials properties yet not considered by existing models. In this paper, we propose SLayerGen, a generative model that produces crystals constrained to be invariant to any space or layer group. SLayerGen consists of coarse-to-fine discrete autoregressive lattice generation; transformer-based autoregressive sampling of Wyckoff positions, elements, and numbers of symmetrically unique atoms; and space or layer group equivariant diffusion of atomic coordinates. For the diffusion component, we corrected an inconsistency in the loss from prior work arising from hexagonal groups being non-orthogonal in fractional coordinates. To facilitate progress in generative modeling of diperiodic materials, we assembled and filtered datasets of monolayers and bilayers, propose relevant evaluation metrics, and developed novel representations for layer group symmetries. For de novo generation of diperiodic materials, SLayerGen achieves consistent performance gains over bulk crystal generative models and is competitive when training jointly on bulk and diperiodic materials.

  PublisherOA PDF

• Point defects in crystalline materials at 100 years

  MRS Bulletin · 2026-05-18

  articleSenior author
  PublisherDOI

• Synthesis, Crystal Structure, and Transport in Ordered Vacancy Compound Hg ₂ SiTe ₄

  Inorganic Chemistry · 2026-03-30

  articleOpen access

  Hg2SiTe4 is found to be stable at room temperature and pressure and crystallizes in the I4̅ space group. The tetragonal compound (a = 6.04681(3) Å, c = 12.01208(9) Å, Z = 2) exhibits p-type electronic conduction and ultralow thermal conductivity (κtotal < 1 W/m K at 50 °C). The crystal structure is determined via charge flipping using TOPAS software to analyze X-ray diffraction data on powder samples. The compound is synthesized from elemental precursors and requires densification before annealing to form the ternary compound, unlike the similar compound Hg2GeTe4. Several synthetic procedures are tested to determine the best method to form the novel compound. Measured thermal and electronic property data are discussed along with first-principles defect calculations to inform future doping or optimization studies. Defect calculations suggest that SiHg2+, VHg2−, and HgSi2− native antisite defects may pin the Fermi level deep within the bandgap. Throughout, we compare the crystallographic and electronic properties of Hg2SiTe4 to those of the similar, previously discovered compound Hg2GeTe4.

  PublisherDOI

• 3D mapping of defects and moiré corrugations via electron ptychography atomic coordinate retrieval

  Science Advances · 2026-05-06

  preprintOpen access

  Defects and reconstructions in two-dimensional (2D) moiré materials cause out-of-plane deformations that strongly modify their electronic properties but are difficult to experimentally access. Here, we solve the 3D atomic coordinates of twisted bilayer WSe 2 with picometer-scale accuracy using multislice electron ptychography (MEP) acquired from a single orientation. The resulting atomic models individually visualize each of the six atomic planes, revealing the curvature of each WSe 2 layer, variations in the interlayer spacing, and the 3D locations of individual vacancies, which lie exclusively in the outer Se planes. We also observe an unexpected type of structural disorder consisting of mixed bending- and breathing-type moiré-induced corrugations that should strongly affect the emergent electronic properties. Broadly, our methods generate 3D atom-by-atom models of a 2D heterointerface from data acquired in about 30 seconds, methods that should unlock routine access to 3D atomic information in 2D systems and catalyze design methods to control out-of-plane deformations.

  PublisherDOI

• The nature of dynamic local order in hybrid lead halide perovskites

  Structural Dynamics · 2025-03-01

  articleOpen access

  Hybrid lead halide perovskite semiconductors (LHPs) are recently reinvigorated class of materials with impressive performance in optoelectronic devices. Unlike the “classical” semiconductors of Si or GaAs, in LHPs the optoelectronic properties are governed by structural fluctuations within the seemingly well-defined high-temperature cubic phase. Recent work has uncovered potential short-range order arising from these fluctuations. However, the origin and structure of this short-range order are unresolved, impeding our understanding of technologically relevant properties including long carrier lifetimes and facile halide migration. Here, I will present a comprehensive exploration into the nature of short-range order in the prototypical LHPs, CH3NH3PbI3 and CH3NH3PbBr3. The true structure of these LHPs is determined with a combination of diffuse scattering, neutron spectroscopy, and molecular dynamics simulations. We find remarkable collective dynamics consisting of a network of two-dimensional pancake-like regions of dynamically tilting lead halide octahedra (lower symmetry) that induce longer ranger intermolecular correlations on the CH3NH3+ sublattice. I will discuss recent experimental results for other LHP compounds that show the type and dimensionality of short-range order is composition dependent. Finally, the impact of this dynamic local structure on charge carrier lifetime and halide migration will be discussed.

  PublisherDOI

• Expressivity of Determinantal Ansatzes for Neural Network Wave Functions

  Journal of Chemical Theory and Computation · 2025-09-17 · 1 citations

  articleOpen access

  Neural network wave functions have shown promise as a way to achieve high accuracy in solving the many-body quantum problem. These wave functions most commonly use a determinant or a sum of determinants to antisymmetrize many-body orbitals, which are described by a neural network. In many cases, the wave function is projected onto a fixed-spin state. Such a treatment is allowed for spin-independent operators; however, it cannot be applied to spin-dependent problems, such as Hamiltonians containing spin–orbit interactions. We show that for spin-independent Hamiltonians, a strict upper bound property is obeyed between a traditional Hartree–Fock-like determinant, full spinor wave function, the full determinant wave function, and a generalized spinor wave function. The relationship between a spinor wave function and the full determinant arises because the full determinant wave function is the spinor wave function projected onto a fixed-spin, after which antisymmetry is implicitly restored in the spin-independent case. For spin-dependent Hamiltonians, the full determinant wave function is not applicable, because it is not antisymmetric. Numerical experiments on the H3 molecule and two-dimensional homogeneous electron gas confirm these bounds.

  PublisherOA PDFDOI

Recent grants

• CAREER: Designing Functionality Into Two-Dimensional Materials Through Defects, Topology, and Disorder

  NSF · $473k · 2016–2022

• Network for Computational Nanotechnology - Hierarchical nanoMFG Node

  NSF · $4.0M · 2017–2023

• DMREF: Discovery and Design of Magnetic Alloys by Simulation and Experiment

  NSF · $674k · 2014–2018

• DMREF: Collaborative Research: Accelerating Thermoelectric Materials Discovery via Dopability Predictions

  NSF · $370k · 2017–2022

Frequent coauthors

• Jiaxing Qu

  University of Illinois Urbana-Champaign

  35 shared

• Jeffrey C. Grossman

  Massachusetts Institute of Technology

  34 shared

• Lídia C. Gomes

  Universidade Estadual Paulista (Unesp)

  34 shared

• Nicola H. Perry

  University of Illinois Urbana-Champaign

  31 shared

• Kara Kearney

  30 shared

• Eric S. Toberer

  27 shared

• Namhoon Kim

  27 shared

• Angus Rockett

  Ida Darwin hospital

  26 shared

Awards & honors

• NSF CAREER Award
• TMS Early Career Faculty Fellow Award
• Emerging Leader Award from the Society of Women Engineers
• Dean's Award for Excellence in Research, University of Illin…
• Dean's Award for Excellence in Research, University of Illin…