Abstract: Understanding the structure and evolution of planets requires a precise quantitative understanding of how matter behaves under extreme conditions (millions of atmospheres of pressure, thousands to millions of Kelvin).  To make progress given the dearth of experimental data in these regimes, we often have no choice but to go back to first principles.  This talk will illustrate how we can start from the Dirac and Schrodinger equations to compute equilibrium and non-equilibrium properties of systems under extreme conditions in ways that inform high energy density experiments and planetary models.  The approach I will outline is highly multifaceted, using methods like Quantum Monte Carlo and Density Functional Theory to generate approximate solutions to Schrodinger’s equation, training interatomic potentials to accelerate times to solution, all while making use of heterogeneous high performance computing systems. 

Bio: Raymond Clay is a Principal Member of Technical Staff in the High Energy Density Theory Department at Sandia National Laboratories in Albuquerque, NM.  He received his PhD in Physics in 2016 from the University of Illinois at Urbana-Champaign under David Ceperley, studying Quantum Monte Carlo methods and their application to Jovian planetary physics.  He joined Sandia National Laboratories as a postdoc in 2016 and was converted to staff in 2018.  He is a developer of the exascale Quantum Monte Carlo code QMCPACK, and while he continues his general work of computational electronic structure theory warm dense matter, he has wide ranging interests in the intersection of electronic structure theory, machine learning, and quantum information.