Mn2.5Ni0.5Sn

[Shabeer ali pc]

Dear VAMPIRE users,

I want to create Heuslar material (Mn2.5Ni0.5Sn) with a tetragonal structure from parent compound of Mn2NiSn What do I have to do in the material file? I have attached the material file of Mn2NiSn to this email.

Also, could you tell me what interactions I should mention in the .ucf file? From where to know these interactions?

Can anyone help me in this regard?

Thanks and regards.

Shabeer

[gabo...@gmail.com]

Something that I have noticed in your Mn2NiSn.mat is that you have:

material[1]:unit-cell-category=4

material[2]:unit-cell-category=4

material[3]:unit-cell-category=4

As described at (1), the "material[1]:unit-cell-category=4" would tag material[1] to material atom site 4. If you intended to that, that's fine.  However, I suspect you want each material assigned to their own atom sites.  In other words:

material[1]:unit-cell-category=1

material[2]:unit-cell-category=2

material[3]:unit-cell-category=3

There was a spinel example that might be helpful for understanding use of the unit-cell-category, which should be at (2).

For the ucf file as seen in (3) or in (4), Jij values can be assigned in the file.

Some VAMPIRE users have been trying to get Jij values using TB2J (5) or TB2J-OpenMX (6) with varying success/failure (7).

The Heusler article at (8) might be of interest to you.  As in it, it looks like they compute Jij values using a software package called Jx (9).  I have not tried it, but it looks potentially possible that Jij values from Jx could be taken and used in the VAMPIRE ucf file.

(1) https://groups.google.com/g/vampire-users/c/QGFtYVB6Kd8/m/aJLRijgZBQAJ

(2) https://groups.google.com/g/vampire-users/c/_YA0slj21hw/m/yzJR5fZmAQAJ

(3) slide 8 of https://vampire.york.ac.uk/resources/workshop2017_day3.pdf (or https://www.youtube.com/watch?v=aS_I8clpGq8)

(4) page 35 of the VAMPIRE 6.0 manual: https://vampire.york.ac.uk/resources/vampire-manual.pdf

(5) https://tb2j.readthedocs.io/en/latest/src/multibinit.html#interface-with-vampire

(6) https://github.com/mailhexu/TB2J-OpenMX

(7) https://groups.google.com/g/vampire-users/c/XQ6KKfLpGxk/m/HEjHqPdJDwAJ

(8) https://arxiv.org/abs/2209.10216v1

(9) https://kaist-elst.github.io/Jx.jl/

Kind Regards,

Gavin

VAMPIRE user