ASTRA, A Transition Density Matrix Approach to the Interaction of Attosecond Radiation with Atoms and Molecules

A new formalism and computer code, ASTRA (AttoSecond TRAnsitions), has been developed to treat the interactions of short, intense radiation with molecules. The formalism makes extensive use of transition density matrices, computed using a state-of-the-art quantum chemistry code (LUCIA), to efficiently calculate the many-body inter-channel-coupling interactions required to simulate the highly correlated electron dynamics due to atoms and molecules exposed to attosecond laser radiation.