error "unknown atom label Ni"

Alloy Theoretic Automated Toolkit (ATAT)
1

Hello All,

I am new to ATAT and am trying to populate Co in Ni and Al sites in L12-Ni3Al. I also have my crange.in file which lists the constraints.

+1.0Ni -3.0Al +1.0Co <= 0.2
1.0Ni >= 0.60
1.0*Al >= 0.15
~

But I keep getting this error: "unknown atom label Ni". When I don’t use crange.in, it works fine. Here is the lat.in file:

3.57 3.57 3.57 90 90 90
1 0 0
0 1 0
0 0 1
0 0 0 Al,Co+1.67
0 0.5 0.5 Ni+0.6,Co+1.67
0.5 0 0.5 Ni+0.6,Co+1.67
0.5 0.5 0 Ni+0.6,Co+1.67

Any suggestions would be really appreciated!

Thanks,
Aakash
~

2

Not a mmaps expert but judging from the lat.in file, you aren’t conserving your atom names.

According to your .in file, your atom names are Ni+0.6, Co+1.67. The composition is determined by your cringe file.

3

I actually used those names for the crange file too. For example, I used:
1.0Ni+0.6 + 1.0Co+1.67 …

But I still get the same error. Any help would be appreciated. I don’t know what I am doing wrong.

4

Hejsan, I’m also new, so I can be wrong.
I’m also testing some alloys with crange.
When I use the crange file, I don’t change my specification in the lat.in file. I leave the constriction of composition just for the crange file.
For me it is working the calculation, but rather slow to find structures.

5

Okay, I think I did not make it clear. The numbers after the atom symbols are the magnetic moments, for example: 0.6 BM for Ni. That tells vasp to do a spin-polarized calculation. But I tried using both Ni+0.6 and Ni for the crange.in files. In both cases, it gives the same error.

Dr. Axel, could you help?

Thanks,
Aakash

6

Sorry for the delayed response (see main forum page for the reasons!)
The problem comes from the fact that the parser for the concentration constraints confuses the label names that include numbers with the coefficients of the equations. I don’t have a fix for that specifically (sorry!). However, here is a way around. Since all your atoms always have the same moment, you could use only Co and Ni as your labels in your lat.in file. In your vasp.wrap file you would put
SUBATOM = s/Co/Co+1.67/g
SUBATOM = s/Ni/Ni+0.6/g

Then, since you have already run mmaps, you need to edit the */str_relax.out file to reflect the new names.
perl -pi.bak -e ‘s/Co+1.67/Co/g; s/Ni+0.6/Ni/g;’ */str_relax.out
(This would not be necessary if this were a fresh new run.)

Note that if your had, say Ni+0.5 and Ni-0.5 as your species, I would use an alphabetical label to distinguish them (e.g. Nip Nim) and use the same SUBATOM trick with each.

7

Dear Dr. Axel,

Thank you so much for the answer. This works perfectly fine :slight_smile:

Thanks again for this trick.

Regards,
Aakash