ATTOMESA: A New Method for Attosecond and Strong-Field Physics in Correlated Multielectron Systems

With the rapid advancements in attosecond physics, the development of efficient and accurate time-dependent quantum chemistry methods has become crucial for investigating ultrafast phenomena in complex systems. Here, we introduce ATTOMESA, highlighting its key features and presenting a first complete set of results on high-harmonic generation (HHG) and photoelectron spectra of simple atomic and molecular systems. Our results, benchmarked against available experimental data and other theoretical approaches, demonstrate the high accuracy and efficiency of ATTOMESA for the description of strong-field phenomena. Additionally, we explore its potential for modeling valence and core-electron dynamics, with applications for streaking and real-time imaging techniques such as high-harmonic spectroscopy (HHS) and light-induced electron diffraction (LIED). These capabilities pave the way for studying a wide range of ultrafast phenomena, including electronic coherence, charge migration, and ultra-fast electron rearrangement in mid-sized molecules.