How to write pp3 pseudopotential for ternaries?

[ndhamrai]

Issue

Based on the code from #https://github.com/zhubonan/airsspy/blob/master/examples/example-1.1.ipynb

and the required information for binaries on #https://airss-docs.github.io/tutorials/examples/#example-108, I wrote the pp in the following way, which works.

pp = "2 12 6 5\nAl S\n# Epsilon\n1.00 1.50\n0.50\n# Sigma\n2.00 1.60\n1.76"

But changing the pp so that ternaries are considered: pp = "3 12 6 5\nAg Sn S\n# Epsilon\n1.00 1.50\n0.50\n# Sigma\n2.00 1.60\n1.76" does not work. Where is the mistake and how are the numbers for epsilon and sigma read and related to the atoms?

Thanks in advance

[zhubonan]

Hi, there are more terms for Epsilon and Sigma with three species, as you now have 6 different pairs instead of three: AA, AB, AC, BB, BC, CC

You see the syntax in example 1.10's ABC.pp:

3 12 6 5
A B C
# Epsilon
1.00 1.50 1.25
0.50 0.75
0.60
# Sigma
2.00 1.60 1.75
1.76 1.5
1.80

[ndhamrai]

Thanks, for that quick answer. It works as it should.