How Many Electrons Does a Molecular Electride Hold

This work has been supported by grants from the Spanish government MICINN (PGC2018-098212−B-C21, PGC2018-098212−B-C22, CTQ2016-80375-P, and EUR2019-103825), Generalitat de Catalunya (2017SGR39), Diputacion Foral de Gipuzkoa (2019-CIEN-000092-01). and Gobierno Vasco-Eusko Jaurlaritza (IT1254-19, PRE_2020_2_0015 and PIBA19-0004). E.R.- C. acknowledges funding from the Juan de la Cierva Program IJCI-2017-34658. We are also grateful for the computational time from the Consorci de Serveis Universitaris de Catalunya (CSUC), DIPC, and the SGI/IZO-SGIker UPV/EHU