What is XChem?:

XChem is a solution for an all-electron ab-initio calculation of the electronic continuum of
molecular systems. XChem combines the tools of quantum chemistry (as implemented in Molcas)
and scattering theory to accurately account for electron correlation in the single-ionization
continuum of atoms, small and medium-size molecules.

XChem applications:

Designed to study molecular photoionization involving multichannel scattering problem.
It is used to

• Represent accurately molecular autoionization and Auger decay beyond the BornOppenheimer approximation.
• Design interfaces compatible with available ab initio Quantum Chemistry packages for a widespread use in molecular ionization problems.
• Keep computational cost at the same level as that required to evaluate bound states at the same level of theory.

Who is XChem for?

XChem is a valuable tool for:

• Researchers in (computational) quantum chemistry or molecular physics interested in
  studying electron dynamics in the ionization continuum of molecules (e.g., photoionization,
  charge migration, etc).
• Laboratories investigating ultrafast phenomena in many-electron atoms, small and medium
  size molecular systems.

Acknowledgements

The research carried out by the authors and giving rise to XChem-v0 software has been conducted
at the Universidad Autonoma de Madrid and has received funding from the European Research
Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) / ERC grant
agreement n° 290853 (ERC-AdG-XCHEM) and under the European Union’s Horizon 2020
research and innovation programme, grant agreement No780284 (ERC-PoC-Imaging-XChem).
XChem-v0 software has been further developed with the support of the Spanish Ministry of Science
and Innotavion, National Research Agency (AEI), and the Regional Funds of the European Union
(FEDER), under projects ref. ref. FIS2016-77889-R and BES-2017-081521, giving rise to XChemv1.
Protection and analysis of XChem-v1 exploitation pathways, and furhter developments, are
been carried out under project ref. PDC2021-121073-I00 funded by MCIN/ AEI
/10.13039/501100011033 and by the European Union “NextGenerationEU”/PRTR.