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Anouar Benali

Computational Scientist

Development and implementation of high accuracy quantum chemistry and computational material science methods for High Performance Computing (HPC)


Dr. Anouar Benali is an Computational Scientist within the Argonne Computational Science division and the Material Science Division. He obtained a B.Sc. and a M.Sc in Physics from the University of Sciences and Technology of Lille (France) in 2007, and a Ph.D. in Theoretical Physical Chemistry from the University of Toulouse (France) in 2010. He was post-doctoral fellow at Argonne National Laboratory (2011-2013) prior to transitioning to his actual position.

His primary research interests are ab initio high accuracy simulation methods for quantum chemistry and material science, with a focus on Quantum Monte Carlo (QMC) methods and selected Configuration Interaction (sCI). Dr. Benali is a developer of the QMCPACK simulation package and the Quantum Package 2.0 (QP2) code. On QMCPACK, his work focuses on implementing and speeding QMC algorithms for the current and future generation of High Performance Computers (HPC). On QP2, his work focuses on implementing sCI algorithms for solids (periodic systems).  

As a method developer, applications interests cover a large spectrum, with a preference for strongly correlated systems and van der Waals dominated systems; since QMC and sCI are many-body methods, e.g explicitly including all electronic correlations and dispersion  forces, it makes them ideal methods for catalysis, semi-conductors, weak interactions (vdW molecules and solids), Transition metal oxides and complexes, multireference and open-shell systems. 

Research Interests

  • Properties of materials and molecules from first principles methods using QMC and sCI:
    • Ground state and excited state properties of strongly correlated electrons material and weakly bonded materials (van der Waals dominated materials):
      • Transition Metal Oxides, (3d and 4d metals including Spin-Orbit Coupling)
      • Van der Waals dominated 2D, and 3D materials (Graphene-like materials)
      • Properties and transitions of magnetic systems.
      • Electronic structure and band structure of semiconductors and storage materials.
      • Energetics and properties of surfaces, defects, adsorption
  • Using multi-determinant wavefunctions to reach high accuracy for open shell molecules and solids using selected CI.
  • Benchmark and asses accuracy of quantum computer algorithms in Quantum Chemistry.
  • High-Performance Computing, Memory and Algorithm optimizations
  • Simulation methods for exploitation of Exascale supercomputers and emergent architectures

Funding and Projects (co)lead:

  • 20172024: Co-Investigator (co-PI) on the Center for Predictive Simulation of Functional Materials, U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.
  • 20172024: Co-Investigator (co-PI) on the Exascale Computing Project, a collaborative effort of two U.S. Department of Energy organizations (Office of Science and the National Nuclear Security Administration) responsible for the planning and preparation of a capable exascale ecosystem, including software, applications, hardware, advanced system engineering, and early test-bed platforms, in support of the nation’s exascale computing imperative.
  • 20172022: Principal investigator on the Aurora Early Science Program on Extending Moore’s Law computing with quantum Monte Carlo” aimed at preparing and porting QMCPACK on the next generation of supercomputer at Argonne National Lab.
  • 20142017: Principal investigator on the Intel Parallel Computing Center at ALCF on Quantum Monte Carlo.
  • 20122017: Co-Investigator Network for ab initio many-body methods: development, education and training” supported through the Predictive Theory and Modeling for Materials and Chemical Science program by the Basic Energy Science, the U.S. Department of Energy (DOE).

Leadership, student mentoring and teaching:

  • Team lead to 2 assistant computational scientists and a computational scientist at CPS division
  • Mentor to 1 current and 3 former postdoctoral researchers.
  • Mentored multiple grad and undergrad students from various universities and countries (University of Pittsburgh, Konkuk University, The University of Illinois in Chicago, Japan Institute of Science and Technology, North Carolina State University)
  • Lecturer at the winter-school 2019 in Engelberg”   Doctoral school of Basel university, Switzerland; Monte Carlo Simulations: A Generic Tool in Computational Sciences”, January 2019

Organizations and committees:

  • Organization of the QMCPACK Workshop 2021 (Virtual)
  • Organization of the QMCPACK Workshop 2019 at ORNL
  • Organization and Chairing of the Quantum Monte Carlo Symposium at the Platform for Advanced Scientific Computing (PASC) Conference 2017 In Lugano, Switzerland.
  • Organization of the QMC summer Training 2016 at UIUC.
  • Organization of the QMC summer Training 2014 at ANL.

Professional Service:

  • Reviewer for APS, ACS, IOP, Elsevier
  • Reviewer for computational readiness for the U.S Department of Energy INCITE program.
  • Provide assistance and expertise for INCITE projects award winners in order to achieve their scientific goals.
  • Prepare and provide DOE with expertise in order to set the specifications of the next HPC platforms in DOE Leadership Computing Facilities.

List of selected Publications:

  • Adsorption of a single Pt atom on graphene: Spin crossing between physisorbed triplet and chemisorbed singlet states” J. Ahn, I. Hong, G. Lee, H. Shin, A. Benali, and Y. Kwon, Phys. Chem. Chem. Phys., (2021) accepted
  • Importance of van der Waals interactions in hydrogen adsorption on a silicon-carbide nanotube revisited with vdW-DFT and quantum Monte Carlo” GI Prayogo, H Shin, A Benali, R Maezono, K Hongo, ACS Omega,  accepted (2021)
  • Optimized structure and electronic band gap of monolayer GeSe from quantum Monte Carlo methods” H Shin, JT Krogel, K Gasperich, PRC Kent, A Benali, O Heinonen, Phys. Rev. Materials 5, 024002 (2021)
  • Quantum Monte Carlo benchmarking of large noncovalent complexes in the L7 benchmark set” A. Benali, H. Shin, O. Heinonen, J. Chem. Phys. 153, 194113 (2020)
  • Towards a Systematic Improvement of the Fixed-Node Approximation in Diffusion Monte Carlo for Solids – A Case Study in Diamond” A. Benali, K. Gasperich, KD Jordan, T Applencourt, Y Luo, MC Bennett et. al, J. Chem. Phys. 153, 184111 (2020)
  • Taming the fixed-node error in diffusion Monte Carlo via range separation” A. Scemama, E. Giner, A. Benali, and PF Loos, J. Chem. Phys. 153, 174107 (2020)
  • Systematic Comparison and Cross-validation of Fixed-Node Diffusion Monte Carlo and Phaseless Auxiliary-Field Quantum Monte Carlo in Solids FD Malone, A Benali, MA Morales, M Caffarel, PRC Kent, L Shulenburger, Phys. Rev. B – 102, 116104® (2020)


Full list of publications can be found here