3.3.3. Osmium
The Os–W–S ternary system is similar to the Ru–W–S ternary system, except there is one intermetallic phase in the Os–W binary system. We denoted this phase, from 64 to 78 at.% W, as OsW3 in our calculation Os is also hexagonally close-packed, but the solubility of W in Os is rather high. We included 30 at.% W solubility in Os (solubility at 1273 K ) in our calculation, but it did not change which phases were in equilibrium with each other. The calculated ternary phase diagram at 298 K, based on the corresponding binary phase diagrams is WS2 dominant, as shown in Fig. 5e.