= ̅ − V = , () = = = ( + )/ = H/Zr ℎ = / ℎ ℎ ℎ ZrH, ZrH and ZrH 2 ℎ = 1.5 ℎ = (α + )/ (α + )/ = ⁄ ℎ ℎ ≡ − = 1 − = 1 , ()