Recorded 01 April 2025. Sarina Sutter of Vrije Universiteit presents "Reduced Density Matrix Functional Theory for the Canonical Ensemble in Finite Basis Set" at IPAM's Optimal Transport for Density Operators: Theory and Numerics Workshop. Abstract: In this talk we want to study one-body reduced density-matrix functional theory for the canonical ensemble in a finite basis set at elevated temperature. Inclusion of temperature guarantees differentiability of the universal functional by occupying all states and additionally not fully occupying the states in a fermionic system. We use convexity of the universal functional and invertibility of the potential-to-1RDM map to show that the subgradient contains only one element which is equivalent to differentiability. This allows us to characterise the v-representable 1RDMs in this setting. Learn more online at: https://www.ipam.ucla.edu/programs/workshops/workshop-i-optimal-transport-for-density-operators-theory-and-numerics/?tab=schedule