ABINIT Discussion Forums

Hello ,
i am using abinit to calculate magnetization property in FeTio3(ilmenite structure) but i am confused with spinat variable,i have fe and ti with each ather,would you guide me to calculate or choose this variable?
Best regards.

spinat breaks the initial spin symmetry and lets you guide the calculation in what you think is the right direction. So, you need to make an initial guess as to the spin order of ilmenite (ferromagnetic? antiferromagnetic? etc) and set spinat accordingly. You have to give a three component vector for each atom (natom) in the cell. Zeros are ok on the atoms that are not magnetically polarized (probably oxygen in your example).

Hello professor,
thank you for your kindness.
Best wishes.

Hello professor,
as i said before i am working on FeTiO3.there are two kind of Fe atoms in this sample(Fe2+ and Fe3+).i have studied some articles about it but i have some problems.there are 6 Fe atoms but i can't underestand which of them have two positive chrge or three positive charge.would you please guide me how can i find the kind of Fe atom?
Thank you for your kindness.
Best regards.

You could compute the ground state density and then use cut3d to compute the amount of charge in a sphere around each atom. Note that this procedure is independent of spinat--you don't need to know which iron is +2 or +3 to use spinat, only a guess as to which atoms are magnetized (iron or titantium).

Hello professor,
Thank you for your kindness.i know in FeTiO3 ,fe is magnetic and i have to get value for it in spinat variable and collinear system we have just z-direction.but i have problem for initial value.i have 6 fe atoms and 6 ti atoms and 18 o atoms in ilmenite structure of FeTiO3 that it is untiferromagnetic so i put spinat this:
spinat 0.0 0.0 1.0
0.0 0.0 -1.0
0.0 0.0 1.0
0.0 0.0 -1.0
0.0 0.0 1.0
0.0 0.0 -1.0
6*0.0
18*0.0
would you please guide me can i use this spinat for my calculation?
Best regards.
Mina.

No, you need a three-component vector for each atom. So the iron atoms are ok but the 6 Ti atoms give 18*0.0 (6x3) and the 18 oxygen atoms give 54*0.0 (18x3) as contributions to spinat.

Hello professor,
Thank you for your kindness.as i saide before there are two kind of Fe atoms in FeTiO3 and as you said me i wanted to calculate ground state to use cut3d ,but i have an problem that FeTiO3 have ilmenite structure in ambient condition and ilmenite is hexagonal with space group 148 but when i use this information i have an error and i have rhombohedral in my out file.would you please guide me what i have done wrong?
my structure input:
natom 30
natrd 3
ntypat 3
typat 6*1 6*2 18*3
znucl 26 22 8
acell 5.0884 5.0884 14.0855 angstrom
angdeg 90 90 120
spgroup 148
spgaxor 1
brvltt -1
xred 0.00000 0.00000 0.35437
0.00000 0.00000 0.14640
0.31743 0.02332 0.24506
my ERROR:
abinit : ERROR -
fillcell : The number of atoms obtained from symmetries, 10
is lower than the input number of atoms, natom= 30
This is not allowed.
but ten atom is concerned to rhombohedral structure.
Best regards.
"gs.in" 35L, 516C

Hello,
as i said i have problem with symmetry finder.would you please guide me to solve my previous question?
Thank you for your kindness.
Best regards.

Hello professor jzwanzig ,
i wana to use cut3d to calculate charge from density file.i have studied that FeTiO3 is ilmenite(R 3)with space group 148 so i used this information but when my job was run i saw rhmbohedral in my out file .would you please guide me what i have done wrong?
my input file:
natom 30
natrd 3
ntypat 3
typat 6*1 6*2 18*3
znucl 26 22 8
acell 5.0884 5.0884 14.0855 angstrom
angdeg 90 90 120
spgroup 148
spgaxor 1
brvltt -1
xred 0.00000 0.00000 0.35437
0.00000 0.00000 0.14640
0.31743 0.02332 0.24506
my ERROR:
abinit : ERROR -
fillcell : The number of atoms obtained from symmetries, 10
is lower than the input number of atoms, natom= 30
This is not allowed.
but ten atom is concerned to rhombohedral structure.
Best regards.
Mina.