Assymetric interaction error in unit cell file

[sejin shin]

Hello!

I'm an undergraduate student and I'm new to using VAMPIRE. I wanted to create a unit cell file for an anti-ferromagnetic BCT structure but encountered the following error:

"Error! Exchange interaction list in unit cell file MnF2.ucf contains the following assymetric interactions:

1 0 8 -1 0 0
2 0 8 -1 -1 0
3 0 8 0 -1 0
4 0 8 0 0 -1
5 0 8 -1 0 -1
6 0 8 -1 -1 -1
7 0 8 0 -1 -1
8 1 8 0 1 0
9 1 8 -1 1 0
10 1 8 -1 0 0
12 1 8 0 1 -1
13 1 8 -1 1 -1
14 1 8 -1 0 -1
15 1 8 0 0 -1
16 2 8 1 1 0
17 2 8 0 1 0
19 2 8 1 0 0
20 2 8 1 1 -1
21 2 8 0 1 -1
22 2 8 0 0 -1
23 2 8 1 0 -1
24 3 8 1 0 0
26 3 8 0 -1 0
27 3 8 1 -1 0
28 3 8 1 0 -1
29 3 8 0 0 -1
30 3 8 0 -1 -1
31 3 8 1 -1 -1
32 4 8 0 0 1
33 4 8 -1 0 1
34 4 8 -1 -1 1
35 4 8 1 0 1
37 4 8 -1 0 0
38 4 8 -1 -1 0
39 4 8 0 -1 0
40 5 8 0 1 1
41 5 8 -1 1 1
42 5 8 -1 0 1
43 5 8 0 0 1
44 5 8 0 1 0
45 5 8 -1 1 0
46 5 8 -1 0 0
48 6 8 1 1 1
49 6 8 0 1 1
50 6 8 0 0 1
51 6 8 1 0 1
52 6 8 1 1 0
53 6 8 0 1 0
55 6 8 1 0 0
56 7 8 1 0 1
57 7 8 0 0 1
58 7 8 0 -1 1
59 7 8 1 -1 1
60 7 8 1 0 0
62 7 8 0 -1 0
63 7 8 1 -1 0

Assymetric interactions are unphysical: please fix the unit cell file ensuring all interactions are symmetric. Exiting."

I thought I considered all the nearest interactions. Could anyone help me with this issue?

[gabo...@gmail.com]

In your MnF2.ucf, I see:

line 20:   0 0 8 0 0 0 1

line 84: 64 8 0 0 0 0 1

I don't see "0 0 8 0 0 0" in the error list.  So, that is probably a good case with symmetric interactions.

In your error list, I see "1 0 8 -1 0 0"

Looking at your MnF2.ucf, there is:

line 21: 1 0 8 -1 0 0 1

The i j in the above line is 0 8.  So, maybe the program is looking for a corresponding i j 8 0 line for making it symmetric, for example:

72 8 0 -1 0 0 1

You might try that to see if it removes or not the "1 0 8 -1 0 0" from the error list.  If it does remove it from the list, then you could repeat that for "2 0 8 -1 -1 0" and then others until they are all removed from the error list.

Kind Regards,

Gavin

VAMPIRE user