The low-temperature structure of LiSH

Density functional theory calculations have been used to predict the ordering of the . . . S-H . . . S-H . . . chains in LiSH and ordered low-temperature structures of this compound. We show that ordering within chains is very strong. On the other hand, the interaction between neighboring chains is so weak that ordering is unlikely to occur on cooling from the dynamically disordered room temperature phase. A structural model suggested earlier for the low-temperature structure is critically discussed and earlier conclusions about the bonding in this structure are quantified. The elastic properties of LiSH are predicted.