Jacob Gruber

Computational Materials Scientist

Summary

Materials Scientist specialized in defect mechanics, atomistic simulation and multiscale modeling in graphite and other inorganic materials systems.

  • Author of 15 peer-reviewed journal articles, including 5 first-author publications
  • Extensive molecular dynamics experience investigating defect behavior, especially in graphite
  • Bridged defect behavior, mechanics, and structure-property links across length scales
  • Developed numerical software and pipelines for HPC systems in Python, C, and C++

Education

PhD, Materials Science

Colorado School of Mines, Golden CO

Drexel University, Philadelphia PA

BS, Materials Science & Physics

University of Illinois at Urbana-Champaign

Appointments

Sandia National Laboratories

Graduate Intern, Livermore CA

Graduate Intern, Albuquerque NM

The HDF Group

Student Programmer, Champaign IL

Experience

Defect Behavior and Mechanics in Graphite

  • Revealed novel buckling behavior in graphite and related layered structures through extensive molecular dynamics effort including thousands of individual simulations
  • Built post-processing analysis library for assigning per-atom deformation tensors based on continuum mechanics, exposing Python interface to performant C modules
  • Modified interatomic force fields for graphite to determine the effect of materials parameters on novel buckling behavior, specifically the elastic tensor and stacking fault energy surface
  • Developed general numerical framework for plane strain problems in anisotropic media
  • Utilized finite element analysis to model mechanics plastically anisotropic polycrystals
  • Performed ab-initio simulation of point defect properties in non-equilibrium graphite systems
  • Evaluated many force fields for specific properties in graphite, titanium, Ti3SiC2, and composites
  • Contributed to regular progress reports to funding providers from the interdisciplinary team
  • Synthesized complex, multifaceted, and non-intuitive data into expressive interactive figures

Mechanics of Nanostructured Metals and Alloys

  • Developed method for transforming mesoscale phase field models into atomistic structures
  • Constructed alloyed grain boundaries using custom C++ Monte-Carlo LAMMPS plugin
  • Investigated the effect of grain boundary character on mechanical properties of nanocrystalline systems, utilizing automated MD simulation pipeline
  • Implemented analysis framework for quantifying plastic and elastic deformation mechanisms
  • Designed atomistic simulation methodology for producing nanoporous foam geometries and post-processing quantification and skeletonization of those geometries
  • Optimized embedded atom method and machine learning interatomic force fields to describe dislocation properties in multiple metallic systems
  • Wrote successful proposals for HPC resource allocations
  • Parametrized dislocation dynamics models from molecular dynamics simulations of dislocation interactions with grain boundaries

Simulation Methods for Deposition of InGaN Films

  • Evaluated novel Stillinger-Weber style force field for In/Ga/N system against experimental and theoretical results in literature, including thermal and point defect properties
  • Designed molecular dynamics method for multi-component chemical vapor deposition
  • Measured point defect and dislocation properties and concentrations across hundreds of simulations, utilizing a bespoke analysis suite
  • Validated the force field and method by comparing simulated defect concentrations to experiment

Grain Boundary Structure–Property Linkages

  • Established automated framework for generating minimum energy grain boundary structures as well as thermodynamically sampled non-equilibrium structures
  • Calculated thermal and mechanical properties for thousands of grain boundaries
  • Developed analysis method for extracting geometric structural elements for use in hierarchical machine learning model, both of isolated grain boundaries and those within polycrystals
  • Constructed framework for initiation of radiation cascades in isolated boundaries and polycrystals, tracking damage evolution in nearby regions of material

Data Visualization and Parallel I/O

  • Wrote virtual file driver for parallel I/O to in-memory file objects
  • Designed and implemented a modular, stackable virtual file driver system
  • Collaborated with the Army Corps of Engineers to design an application for visualization and manipulation of real-time spatial data
  • Optimized algorithms and improved debugging and testing within the parallel I/O API

Technical Skills

Simulation & Modeling

  • Expert in Molecular Dynamics Simulation using LAMMPS
  • Proficient in DFT using VASP and Quantum Espresso
  • Finite Element Analysis using ABAQUS
  • Force-field development and validation
  • Bespoke continuum models: e.g. anisotropic elasticity and microstructure evolution
  • Multiscale modeling linking results from multiple simulation methodologies

Scientific Software Development

  • Numerical codes in Python, C, C++, and Fortran
  • Extension existing large software frameworks with custom plugins
  • HPC workflows and performance-oriented computing
  • Automated post-processing, analysis, and visualization pipelines
  • Contributions to major open source projects like HDF5

Achievements and Honors

  • Author of 15 publications, including 5 first-author
  • Presented 6 works at conferences and contributed to dozens of other presentations
  • Recipient of GAANN fellowship, 2017 Young Scientist Symposium Invite, and 4 other scholarships

Selected Publications

Bending the rules: Strain accommodation in layered crystalline solids through nanoscale buckling over dislocations

J. Gruber, G. Plummer, G.J. Tucker

Journal of the Mechanics and Physics of Solids (2024)

Characterization of ripplocation mobility in graphite

J. Gruber, M.W. Barsoum, G.J. Tucker

Materials Research Letters (2020)

Molecular dynamics studies of defect formation during heteroepitaxial growth of InGaN alloys on (0001) GaN surfaces

J. Gruber, X.W. Zhou, R.E. Jones, S.R. Lee, G.J. Tucker

J Appl Phys (2017)

Development of physically based atomistic microstructures: The effect on the mechanical response of polycrystals

J. Gruber, H. Lim, F. Abdeljawad, S. Foiles, G.J. Tucker

Computational Materials Science (2017)

Evidence for Bulk Ripplocations in Layered Solids

J. Gruber, A.C. Lang, J. Griggs, M.L. Taheri, G.J. Tucker, M.W. Barsoum

Sci Rep (2016)