Deriving and Implementing Stress Tensor Calculation in the Real-Space Adaptive-Mesh Density Functional Theory Code – MELIORA*

First-principles modeling of the warm dense matter regime has historically been challenging, but recent advancements in high performance computing hardware and the emergence of novel algorithms have allowed such calculations to be possible with only moderate resource allocations. MELIORA is an emerging all-electron mixed stochastic-deterministic density functional theory code based on the real space adaptive-mesh-refinement finite element method aiming to achieve simulations of 10^3 - 10^4 electrons at the multi-eV temperature regime. Here, we discuss the derivation and numerical implementation of an efficient stress tensor calculation within the MELIORA code, focusing on the Maxwell stress tensor and the Hellman-Feynmann and virial theorems. Stress tensor results from MELIORA simulations of warm dense matter will be compared with experiments and results from other DFT codes.