Calculation of ferromagnetic states in metastable bcc and hcp Ni by projector-augmented wave method

Based on a projector-augmented wave method, ab initio calculations reveal that hcp Ni is ferromagnetic with a magnetic moment of 0.59μB, which is slightly smaller than 0.60μB in the stable fcc Ni. For bcc Ni, it is found that a ferromagnetic is energetically favored when the lattice constant a>2.69Å, below which there may be a coexisting state of ferromagnetic and nonmagnetic behaviors. Interestingly, although bcc Ni has a smallest magnetic moment of 0.55μB, it has a largest average atomic volume among the three structures, differing sharply from the cases of Fe and Co.