Combinatorial sets are used to study a variety of modifications to a base structure through substitution of elements at particular atomic positions. To this end it is possible to specify what elements are substituted for each atomic site in a structure and specify a different substitution rule for each position as well.

Overview

This feature lets users create multiple materials at the same time using an extended syntax for crystal basis (compared with regular XYZ format): an input line that has element characters separated by slashes or commas.

Si, P    0.0 0.0 0.0
Si       0.5 0.5 0.0

In the above example we have added P atom into the crystal basis of FCC Silicon such that combinatorial set will contain 2 materials - Si2 and SiP in diamond FCC lattice arrangements

How to access

Open left-hand sidebar and navigate to "Materials" page, select "Create New" action in toolbar, then choose combinatorial set generation dialog - .

Permutations

Permutations change all elements in basis "at once" when separated by slashes

1st scenario - input

Si/Ge/As 0.0 0.0 0.0
Si/Ge    0.5 0.5 0.0

In case slashes ("/") are used as separators, the elements are changed all at once, eg. there will be 3 total bases created in the above example:

Case 1 - structure generated

Si 0.0 0.0 0.0
Si 0.5 0.5 0.0

Case 2 - structure generated

Ge 0.0 0.0 0.0
Ge 0.5 0.5 0.0

Case 3 - structure generated

As 0.0 0.0 0.0
Ge 0.5 0.5 0.0

Combinations

2nd scenario - input

Si,Ge,As 0.0 0.0 0.0
Si,Ge    0.5 0.5 0.0

In case commas (",") are used as separators, the elements are changed one at a time, eg. there will be 6 total bases created in the example above:

Case 1 - structure generated

Si 0.0 0.0 0.0
Si 0.5 0.5 0.0

Case 2 - structure generated

Si 0.0 0.0 0.0
Ge 0.5 0.5 0.0

Case 3 - structure generated

Ge 0.0 0.0 0.0
Si 0.5 0.5 0.0

Case 4 - structure generated

Si 0.0 0.0 0.0
Si 0.5 0.5 0.0

Case 5 - structure generated

As 0.0 0.0 0.0
Si 0.5 0.5 0.0

Case 6 - structure generated

As 0.0 0.0 0.0
Ge 0.5 0.5 0.0

Materials set

Materials in the set are first added to the current Material Editor session. One can see the total number and navigate to each by using a toolbar. Each individual material in the set can then be further adjusted/edited as needed. The set can then be saved to appear in the "Materials" list.