{'fraction_non_alphanumeric': 0.028526148969889066, 'fraction_numerical': 0.0, 'mean_word_length': 6.101123595505618, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
The Lippmann–Schwinger equation in electron–molecule scattering theory and the many-body Brillouin–Wigner expansion

The Lippmann–Schwinger equation for the scattering of electrons by atoms and molecules is investigated from the perspective of Brillouin–Wigner perturbation theory. It is shown that the solution of the Lippmann–Schwinger can be obtained from many-body Brillouin–Wigner methods for bound-state problems. In particular, the equations of many-body Brillouin–Wigner coupled cluster theory for bound-state systems can be shown to lead directly to equations for the amplitudes for electron–molecule scattering processes.