The free energy surface of Li 4 Br 4 shows structures analogous to those obtained for Li 4 Cl 4 with a preference for more solvated species (Figure ). The tetrasolvated pseudo-cubane C4 appears as a rather shallow metastable state, and there is a clear thermodynamic preference for an open form of the cube, C5, with a broken Li-Br bond and an additional THF at that lithium. Analo- gously to LiCl, C5 further degrades through the cleavage of a second Li-Br bond, resulting in cyclic R6 and a cis boat-like structure B6 in a 6:1 ratio. As in the case of LiCl, the structural arrangement in B6 corresponds to the core unit for THF-solvated crystalline LiBr polymers. Further down the solvation pathway, the FES of Li 4 Br 4 exhibits a greater propensity for cyclic and bridged Lithium iodide Unlike LiCl and LiBr, where dimeric units are notably thermodynamically disfavored compared to the tetrameric species, the free energy landscape of Li 4 I 4 leads to the spontaneous degradation of the tetramer into smaller moieties (Figure ). In our simulations, a starting pseudo-cubane type C4 structure promptly breaks down to form species of lower molecular weight through the transient formation of non-bridging moieties. Thus, the characterization of a tetrameric Li 4 I 4 (OEt 2 ) 8 27,39 out of diethyl ether is an example of the difference in structural preference in the crystalline state and in solution. Such non-bridging moieties are observed to initiate the separation into dimers D4 already along the one-dimensional profile at the short AIMD timescales, indicating a preference for smaller aggregates (Figure ). While dimeric moieties can also exist in a more solvated form (D5), where one Li-I bond is cleaved to accommodate an additional THF at the lithium, the fully connected dimers remain more favored. Various mixtures of dimers and monomers are found further down the FES, where the fragmentation into monomeric species occurs beyond a barrier of 7 kcal mol -1 .