Signatures of such MCB formation have been observed in static DFT calculations performed on [Li(NH 3 ) + 4 • e -@(NH 3 ) n ] ion-pairs, ab initio molecular dynamics simulations on the fluid near saturation, 107 and even periodic calculations on Li(NH 3 ) 4 solid phases. In fact, TD-DFT (time-dependent DFT) calculations of the absorption spectra of ion-pairs with n = 2, 3, 4, 8 yielded absorption spectra whose profile, including both the maximum in the absorption and the long tail, agreed well with experimental measurements, supporting the assertion that such species might be important constituents of metal ammonia solutions, and providing an alternative to the Jortner picture.