Krylov-space algorithms for time-dependent Hartree-Fock and density functional computations

A fast, low memory cost, Krylov-space-based algorithm is proposed for the d iagonalization of large Hamiltonian matrices required in time-dependent Har tree-Fock (TDHF) and adiabatic time-dependent density-functional theory (TD DFT) computations of electronic excitations. A deflection procedure based o n the symplectic structure of the TDHF equations is introduced and its capa bility to find higher eigenmodes of the linearized TDHF operator for a give n numerical accuracy is demonstrated. The algorithm may be immediately appl ied to the formally-identical adiabatic TDDFT equations. (C) 2000 American Institute of Physics. [S0021-9606(00)30425-1].