Mg2IrH6 (Sanna et al.) stretch share of H S 57.6% lam 2.13->2.62 Tc 126.5->153.6 K (+21.5%) S ratio 1.0000 Mg2IrH6 (Dolui et al.) stretch share of H S 62.7% lam 2.52->3.39 Tc 165.3->201.3 K (+21.8%) S ratio 1.0000 Mg2RhH6 (Sanna et al.) stretch share of H S 60.6% lam 1.27->1.69 Tc 79.8->111.3 K (+39.4%) S ratio 1.0000 Mg2PtH6 (Sanna et al.) stretch share of H S 3.0% lam 1.38->1.12 Tc 90.1->68.0 K (-24.5%) S ratio 1.0000