## Alfredo Correa Tedesco | 18-ERD-031

### Project Overview

We developed unique capabilities for the computational prediction of electrical, optical, and thermal transport properties from quantum simulations. Using a recently developed theory of microscopic quantum transport, we were able to model compressed metallic hydrogen and its nonlinear and out-of-equilibrium contributions in electrical and thermal transport. This theory was implemented in the open-source, real-space, time-dependent, density functional theory code known as Octopus. This code and methodology creates a unique capability for modeling electron transport relevant to multiple applications. For example, we used our modifications to Octopus to determine the nonlinear conductivity of warm dense hydrogen for the first time, a system relevant to inertial confinement fusion campaigns.

### Mission Impact

Our work supports Lawrence Livermore National Laboratory's core competency in high-energy-density (HED) science, as well as our mission-relevant work in inertial confinement fusion (ICF) science, including efforts to characterize and understand the behavior of HED systems. In addition, this research supports NNSA and Laboratory goals in stockpile stewardship, which is dependent on a comprehensive understanding of material processes under extreme conditions. It also enhances the Laboratory’s core competency in high-performance computing, simulation, and data science.

### Publications, Presentations, and Patents

Andrade, X., et al. 2018. "Negative differential conductivity in liquid aluminum from real-time quantum simulations." *The European Physical Journal B*, 91, 10: 229. LLNL-JRNL-715217

Grabowski, P. E., et. al. 2020. "Review of the First Charged-Particle Transport Coefficient Comparison Workshop," *High Energy Density Physics*, 37, 100905. doi:10.1016/j.hedp.2020.100905. LLNL-JRNL-782022

Herriman, J., and B. Fultz. 2020. "Phonon thermodynamics and elastic behavior of GaAs at high temperatures and pressures." *Phys. Rev. B* 101, 214108. LLNL-JRNL-800378

Tancogne-Dejean, N., et al. 2020. "Octopus, a computational framework for exploring light-driven phenomena and quantum dynamics in extended and finite systems." *The Journal of Chemical Physics* 152, 12: 124119. LLNL-JRNL-798921

Ullah, R. "Negative Differential Conductivity in Semiconductors from First Principles." APS March Meeting, Boston, MA, March 2019. LLNL-ABS-760760