Comment on "Structure Prediction of Li-Sn and Li-Sb Intermetallics for Lithium-Ion Batteries Anodes''

In a recently published article Mayo et al.[Chemistry of Materials 2017, 29, 5787] presented the ground state crystal structures of various experimentally unknown Li-Sn intermetallic compounds at ambient pressure (~0 GPa) and 0 K temperature using ab-initio random structure searching method (AIRSS) with high-throughput screening from the Inorganic Crystal Structure Database (ICSD).\cite{AIRSS} In their study, besides the experimentally known phases of Li-Sn such as, $\mathrm{L}{\mathrm{i}}_2\mathrm{S}{\mathrm{n}}_5$ ($\mathrm{P}4\mathrm{/}\mathrm{m}\mathrm{b}\mathrm{m}$),$\mathrm{L}{\mathrm{i}}_1\mathrm{S}{\mathrm{n}}_1$ ($\mathrm{P}2\mathrm{/}\mathrm{m}$, $\mathrm{I}{4}_1\mathrm{/}\mathrm{a}\mathrm{m}\mathrm{d}$), $\mathrm{L}{\mathrm{i}}_7\mathrm{S}{\mathrm{n}}_3$ ($\mathrm{P}{2}_1\mathrm{/}\mathrm{m}$), $\mathrm{L}{\mathrm{i}}_5\mathrm{S}{\mathrm{n}}_2$ ($\mathrm{R}\bar{3}\mathrm{m}$), $\mathrm{L}{\mathrm{i}}_{13}\mathrm{S}{\mathrm{n}}_5$ ($\mathrm{P}\bar{3}\mathrm{m}1$), $\mathrm{L}{\mathrm{i}}_7\mathrm{S}{\mathrm{n}}_2$ ($\mathrm{C}\mathrm{m}\mathrm{m}\mathrm{m}$), and $\mathrm{L}{\mathrm{i}}_{17}\mathrm{S}{\mathrm{n}}_4$ ($\mathrm{F}\bar{4}3\mathrm{m}$), Mayo et al. also reported two previously unknown stable phases for Li-Sn such as, $\mathrm{L}{\mathrm{i}}_8\mathrm{S}{\mathrm{n}}_3$-$\mathrm{R}\bar{3}\mathrm{m}$ and $\mathrm{L}{\mathrm{i}}_7\mathrm{S}{\mathrm{n}}_2$-$\mathrm{P}\bar{1}$ along with several Li-Sn metastable phases ($\mathrm{L}{\mathrm{i}}_1\mathrm{S}{\mathrm{n}}_2$, $\mathrm{L}{\mathrm{i}}_2\mathrm{S}{\mathrm{n}}_3$, $\mathrm{L}{\mathrm{i}}_7\mathrm{S}{\mathrm{n}}_9$, $\mathrm{L}{\mathrm{i}}_3\mathrm{S}{\mathrm{n}}_2$, $\mathrm{L}{\mathrm{i}}_5\mathrm{S}{\mathrm{n}}_3$, ${\mathrm{L}{\mathrm{i}}_2\mathrm{S}\mathrm{n}}_1$, $\mathrm{L}{\mathrm{i}}_3\mathrm{S}{\mathrm{n}}_1$, $\mathrm{L}{\mathrm{i}}_4\mathrm{S}{\mathrm{n}}_1$, $\mathrm{L}{\mathrm{i}}_5\mathrm{S}{\mathrm{n}}_1$, and $\mathrm{L}{\mathrm{i}}_7\mathrm{S}{\mathrm{n}}_1$) which lie within 20 meV/atom from the convex hull tie-line. However, while going through their article, we noticed a significant inconsistency and contradictions in their results. Moreover, a one-to-one comparison with our published results\cite{Sen@2017} revealed a disagreement in the symmetry of $\mathrm{L}{\mathrm{i}}_3\mathrm{S}{\mathrm{n}}_1$, $\mathrm{L}{\mathrm{i}}_7\mathrm{S}{\mathrm{n}}_2$, $\mathrm{L}{\mathrm{i}}_4\mathrm{S}{\mathrm{n}}_1$, $\mathrm{L}{\mathrm{i}}_5\mathrm{S}{\mathrm{n}}_1$, and $\mathrm{L}{\mathrm{i}}_7\mathrm{S}{\mathrm{n}}_1$ discussed by Mayo et al.}