upward

Solid

C L Guillaume, E Gregoryanz, O Degtyareva, M I McMahon, M Hanfland, S Evans, M Guthrie, S V Sinogeikin, H K Mao, Cold melting and solid structures of dense lithium, Nat Phys 7, 211 (2011)

A W Overhauser, Crystal Structure of Lithium at 4.2 K, PRL 53, 64 (1984)