The software package FELLA has been written for basic research in atomic, molecular, and optical physics. The atomic physics programs treat the atomic electronic structure in Hartree-Fock-Slater approximation and the interaction of electrons with light of up to two colors. The molecular physics programs treat the x-ray absorption by laser-aligned molecules. An optical physics code describes the propagation of a laser and x-rays through a gaseous medium. Especially, FELLA has been inspired by the upcoming x-ray free electron lasers to study atoms and molecules in their light in combination with intense optical lasers. However FELLA is more general and has been used so far to study atoms and molecules in the light of third-generation synchrotrons.

Find FELLA (Free Electron Laser Atomic, Molecular, and Optical Physics Program Package) at: http://chemistry.anl.gov/Fundamental_Interactions/FELLA_main.shtml

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