Recorded 02 May 2022. Yingzhou Li of Duke University presents "Fast Algorithms for FCI excited states" at IPAM's Large-Scale Certified Numerical Methods in Quantum Mechanics Workshop. Abstract: Fast algorithms are proposed for the electronic structure excited-state calculation in the configuration interaction framework. All of them are based or inspired by an unconstrained nonconvex optimization problem, which is a reformulation of the eigenvalue problem. Global convergence to excited states instead of their invariant subspace is guaranteed almost surely. Locally, algorithms converge linearly with convergence rate depending on energy gaps. Momentum acceleration, exact linesearch, and column locking are incorporated to further accelerate algorithms and reduce computational costs. We demonstrate the efficiency of these algorithms on a few FCI matrices. Learn more online at: http://www.ipam.ucla.edu/programs/workshops/workshop-iii-large-scale-certified-numerical-methods-in-quantum-mechanics/?tab=schedule