AM_Mannardite
Formula: Ba.517 (Ti2.984 V.508 Cr.508) O8.483 H2
Name: Mannardite
Unit cell: 14.357 14.357 5.908 90.0 90.0 90.0 , V=1217.78
Space group: I141/A1 (1)

Szymanski J T , The Canadian Mineralogist , 24 (1986) p.67-78, The crystal structure of mannardite, a new hydrated cryptomelane-group, (hollandite) mineral with a doubled short axis