Phase stability and electronic structure in ZrAl3 compound

The relative stabilities of L1(2), DO22, and DO23 structures in the ZrAl3 i ntermetallic compound have been investigated employing the Vienna ab initio simulation package (VASP). The effects due to the tetragonal distortion of the D0(22) and D0(23) structures are important. The effect of the cell-int ernal displacements of the atoms in the D0(23) structure is studied. The mo re stable structure is D0(23) followed by D0(22) and by L1(2). The calculat ions show that at high pressure L1(2) becomes more stable than D0(22) The e nergies of formation of ZrAl3 in the L1(2) D0(22), and D0(23), structures a re calculated. The computed electronic densities of states show that each s tructure has a pseudo gap in the density of states distribution. The prefer red crystal structure is the one in which the Fermi level lies in the pseud o gap and for which the density of states at the Fermi level is the lowest. The energetic results are discussed in the framework of the ANNNI model. ( C) 2001 Elsevier Science B.V. All rights reserved.