Identifying sources of error in finite temperature calculations for molecules and solids using density matrix quantum Monte Carlo

Density matrix quantum Monte Carlo (DMQMC) calculates exact-on-average finite temperature electronic energies in a finite basis. This method has shown promise when applied to model systems like the electron gas (Phys. Rev. Lett. 117, 115701) but it is not well understood whether these findings are transferrable to real systems and to what extent strong correlation can affect our ability to run calculations on a system. Calculations on small molecules and solids (in a periodic basis set) will be presented including a resolution to previous convergence issues for the H₁₀ chain. Finally, the computational cost scaling of DMQMC will be identified.