Messages

1

General Questions and Answers / CIF export problem

« on: June 26, 2025, 15:34 »

Hello!

Please tell me why the Ni cell, which has an fcc structure with the lattice parameter a=b=c=3.5249 A and angles alpha=beta=gamma= 90 deg., when exported from Quantum ATK to a CIF file, the angles change to 60 deg., and the lattice parameter to 2.49248 A? It seems like everything should be preserved, what's wrong here?

data_global
_cell_length_a 2.49248
_cell_length_b 2.49248
_cell_length_c 2.49248
_cell_angle_alpha 60
_cell_angle_beta 60
_cell_angle_gamma 60
_symmetry_space_group_name_H-M 'P -1'
loop_
_symmetry_equiv_pos_as_xyz
  'x,y,z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
Ni 0 0 0

2

General Questions and Answers / Ternary CoNiFe Alloy

« on: August 1, 2024, 17:26 »

Hello, dear participants of Quantum ATK Forum!

I try to build the unit cell of ternary alloy Co60Ni20Fe20 and determine total magnetic moment/unit cell.
For a such composition I set that Ni, Fe and Co atoms have 4a(0;0;0), 4b(0.5;0.5;0.5) and 4c(0.25;0.25;0.25) Wyckoff positions, respectively.
What is the best way to generate the crystal structure of Co60Ni20Fe20 in QATK?

Unfortunately, I can't find that whether the "Substitutional Alloy", "Heusler Alloy" and "Generic Alloy" options make it possible to fix atoms in different positions with given atom fractions or not.

Thanks for your help!