Be after capture decay - absolute energies, transitions and shake probabilities*

The development of high-resolution superconducting tunnel junction (STJ) quantum sensors has recently allowed for direct measurements of ⁷Li recoils following ⁷Be electron capture decay through the direct implementation of ⁷Be+ ions into the sensor. The main goal of the BeEST experiment is the search of physics beyond the standard model (BSM) in the neutrino sector.  In the first two Phases of the experiment, details in the spectral response have shown disagreement with available theoretical values in the literature, primarily from the atomic structure. Therefore, an effort on the understanding of the atomic relaxation has to be accomplished.  In this work, we present the steps towards the full calculation of the atomic relaxation process after the ⁷Be decay. Two approaches have been used, one using the Multiconfiguration Dirac Fock and General Matrix Element (MCDFGME) Code and another using the Flexible Atomic Code (FAC). All possible transition energies and relative intensities of all shake processes will be presented.