Recorded 02 May 2022. Julien Toulouse of Sorbonne University, LCT, presents "Basis-set correction based on density-functional theory: Rigorous framework for a one-dimensional model" at IPAM's Large-Scale Certified Numerical Methods in Quantum Mechanics Workshop. Abstract: We reexamine the recently introduced basis-set correction theory based on density-functional theory consisting in correcting the basis-set incompleteness error of wave-function methods using a density functional. We use a one-dimensional model Hamiltonian with delta-potential interactions which has the advantage of making easier to perform a more systematic analysis than for three-dimensional Coulombic systems while keeping the essence of the slow basis convergence problem of wave-function methods. We provide some mathematical details about the theory and propose a new variant of basis-set correction which has the advantage of being suited to the development of an adapted local-density approximation. We show indeed how to develop a local-density approximation for the basis-set correction functional which is automatically adapted to the basis set employed, without resorting to range-separated density-functional theory as in previous works, but using instead a finite uniform electron gas whose electron-electron interaction is projected on the basis set. The work puts the basis-set correction theory on firmer grounds and provides an interesting strategy for the improvement of this approach. Learn more online at: http://www.ipam.ucla.edu/programs/workshops/workshop-iii-large-scale-certified-numerical-methods-in-quantum-mechanics/?tab=schedule