This page documents an OPTIMADE Property Definition. See https://schemas.optimade.org/ for more information.

**ID: https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/elements_ratios**

`elements_ratios`

**Property name:** Elements ratios

**Description:** Relative proportions of different elements in the structure.

**Type:** list

**Requirements/Conventions**:

- Composed by the proportions of elements in the structure as a list of floating point numbers.
- The sum of the numbers MUST be 1.0 (within floating point accuracy)
- MUST refer to the same elements in the same order, and therefore be of the same length, as
`elements`

, if the latter is provided.

**Query examples**:

- Note: Useful filters can be formulated using the set operator syntax for correlated values. However, since the values are floating point values, the use of equality comparisons is generally inadvisable.
- OPTIONAL: a filter that matches structures where approximately 1/3 of the atoms in the structure are the element Al is:
`elements:elements_ratios HAS ALL "Al":>0.3333, "Al":<0.3334`

.

**Examples:**

`[1.0]`

`[0.3333333333333333, 0.2222222222222222, 0.4444444444444444]`

**JSON definition:**

```
{
"$id": "https://schemas.optimade.org/defs/v1.2/properties/optimade/structures/elements_ratios",
"$schema": "https://schemas.optimade.org/meta/v1.2/optimade/property_definition.json",
"title": "Elements ratios",
"x-optimade-type": "list",
"x-optimade-definition": {
"label": "elements_ratios_optimade_structures",
"kind": "property",
"version": "1.2.0",
"format": "1.2",
"name": "elements_ratios"
},
"x-optimade-dimensions": {
"names": [
"dim_elements"
]
},
"type": [
"array",
"null"
],
"description": "Relative proportions of different elements in the structure.\n\n**Requirements/Conventions**:\n\n- Composed by the proportions of elements in the structure as a list of floating point numbers.\n- The sum of the numbers MUST be 1.0 (within floating point accuracy)\n- MUST refer to the same elements in the same order, and therefore be of the same length, as `elements`, if the latter is provided.\n\n**Query examples**:\n\n- Note: Useful filters can be formulated using the set operator syntax for correlated values.\n However, since the values are floating point values, the use of equality comparisons is generally inadvisable.\n- OPTIONAL: a filter that matches structures where approximately 1/3 of the atoms in the structure are the element Al is: `elements:elements_ratios HAS ALL \"Al\":>0.3333, \"Al\":<0.3334`.",
"examples": [
[
1.0
],
[
0.3333333333333333,
0.2222222222222222,
0.4444444444444444
]
],
"x-optimade-unit": "inapplicable",
"items": {
"x-optimade-type": "float",
"type": [
"number"
],
"x-optimade-unit": "dimensionless",
"minimum": 0.0,
"maximum": 1.0
}
}
```