Magnetically driven loss of centrosymmetry in metallic Pb2CoOsO6 by Princep, AJ, Feng, HL, Guo, YF, Lang, F, Weng, HM, Manuel, P, Khalyavin, D, Senyshyn, A, Rahn, MC, Yuan, YH, Matsushita, Y, Blundell, SJ, Yamaura, K, Boothroyd, AT