Route providing computed oxidation state data for a material following the methodology employed by the [BVAnalyzer](https://pymatgen.org/pymatgen.analysis.bond_valence.html) in Pymatgen. Note that oxidation state data has not been calculated for all materials in the Materials Project database. See the `OxidationStateDoc` schema for a full list of fields returned by this route.
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openapi: 3.2.0
info:
title: Materials Project Materials Oxidation States API
description: The Materials Project API allows anyone to have direct access to current, up-to-date information from the Materials Project database in a structured way.
version: 0.86.4rc5.dev1+g77c2c1315
x-logo:
url: https://raw.githubusercontent.com/materialsproject/emmet/master/emmet-api/emmet/api/core/assets/mp_logo_small.png
security:
- ApiKeyAuth: []
tags:
- name: Materials Oxidation States
description: Route providing computed oxidation state data for a material following the methodology employed by the BVAnalyzer in Pymatgen. Note that oxidation state data has not been calculated for all materials in the Materials Project database. See the `OxidationStateDoc` schema for a full list of fields returned by this route.
paths:
/materials/oxidation_states/:
get:
tags:
- Materials Oxidation States
summary: Get OxidationStateDoc documents
operationId: search_materials_oxidation_states__get
parameters:
- name: material_ids
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Comma-separated list of material_id values to query on
title: Material Ids
description: Comma-separated list of material_id values to query on
- name: formula
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: Query by formula including anonymized formula or by including wild cards. A comma delimited string list of anonymous formulas or regular formulas can also be provided.
title: Formula
description: Query by formula including anonymized formula or by including wild cards. A comma delimited string list of anonymous formulas or regular formulas can also be provided.
- name: chemsys
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: A comma delimited string list of chemical systems. Wildcards for unknown elements only supported for single chemsys queries
title: Chemsys
description: A comma delimited string list of chemical systems. Wildcards for unknown elements only supported for single chemsys queries
- name: possible_species
in: query
required: false
schema:
type: string
description: Comma delimited list of element symbols appended with oxidation states. (e.g. Cr2+,O2-)
title: Possible Species
description: Comma delimited list of element symbols appended with oxidation states. (e.g. Cr2+,O2-)
- name: _page
in: query
required: false
schema:
type: integer
description: Page number to request (takes precedent over _limit and _skip).
title: ' Page'
description: Page number to request (takes precedent over _limit and _skip).
- name: _per_page
in: query
required: false
schema:
type: integer
description: Number of entries to show per page (takes precedent over _limit and _skip). Limited to 1000.
default: 100
title: ' Per Page'
description: Number of entries to show per page (takes precedent over _limit and _skip). Limited to 1000.
- name: _skip
in: query
required: false
schema:
type: integer
description: Number of entries to skip in the search.
default: 0
title: ' Skip'
description: Number of entries to skip in the search.
- name: _limit
in: query
required: false
schema:
type: integer
description: Max number of entries to return in a single query. Limited to 1000.
default: 100
title: ' Limit'
description: Max number of entries to return in a single query. Limited to 1000.
- name: _fields
in: query
required: false
schema:
type: string
description: 'Fields to project from OxidationStateDoc as a list of comma separated strings. Fields include: `builder_meta` `nsites` `elements` `nelements` `composition` `composition_reduced` `formula_pretty` `formula_anonymous` `chemsys` `volume` `density` `density_atomic` `symmetry` `material_id` `deprecated` `deprecation_reasons` `last_updated` `origins` `warnings` `structure` `property_name` `possible_species` `possible_valences` `average_oxidation_states` `method`'
title: ' Fields'
description: 'Fields to project from OxidationStateDoc as a list of comma separated strings. Fields include: `builder_meta` `nsites` `elements` `nelements` `composition` `composition_reduced` `formula_pretty` `formula_anonymous` `chemsys` `volume` `density` `density_atomic` `symmetry` `material_id` `deprecated` `deprecation_reasons` `last_updated` `origins` `warnings` `structure` `property_name` `possible_species` `possible_valences` `average_oxidation_states` `method`'
- name: _all_fields
in: query
required: false
schema:
type: boolean
description: Include all fields.
default: false
title: ' All Fields'
description: Include all fields.
- name: license
in: query
required: false
schema:
anyOf:
- enum:
- BY-C
- BY-NC
- All
type: string
- type: 'null'
description: Query by license. Can be commercial or non-commercial, or both
default: BY-C
title: License
description: Query by license. Can be commercial or non-commercial, or both
responses:
'200':
description: Search for a OxidationStateDoc
content:
application/json:
schema:
$ref: '#/components/schemas/Response_OxidationStateDoc_'
'422':
description: Validation Error
content:
application/json:
schema:
$ref: '#/components/schemas/HTTPValidationError'
components:
schemas:
OxidationStateDoc:
properties:
builder_meta:
anyOf:
- $ref: '#/components/schemas/EmmetMeta'
- type: 'null'
description: Builder metadata.
nsites:
anyOf:
- type: integer
- type: 'null'
title: Nsites
description: Total number of sites in the structure.
elements:
anyOf:
- items:
type: string
type: array
- type: 'null'
title: Elements
description: List of elements in the material.
nelements:
anyOf:
- type: integer
- type: 'null'
title: Nelements
description: Number of elements.
composition:
anyOf:
- additionalProperties:
type: number
type: object
- type: 'null'
title: Composition
description: Full composition for the material.
composition_reduced:
anyOf:
- additionalProperties:
type: number
type: object
- type: 'null'
title: Reduced Composition
description: Simplified representation of the composition.
formula_pretty:
anyOf:
- type: string
- type: 'null'
title: Pretty Formula
description: Cleaned representation of the formula.
formula_anonymous:
anyOf:
- type: string
- type: 'null'
title: Anonymous Formula
description: Anonymized representation of the formula.
chemsys:
anyOf:
- type: string
- type: 'null'
title: Chemical System
description: Dash-separated string of elements in the material.
volume:
anyOf:
- type: number
- type: 'null'
title: Volume
description: Total volume for this structure in ų.
density:
anyOf:
- type: number
- type: 'null'
title: Density
description: Density in g/cm³.
density_atomic:
anyOf:
- type: number
- type: 'null'
title: Packing Density
description: The atomic packing density in ų/atom.
symmetry:
anyOf:
- $ref: '#/components/schemas/SymmetryData'
- type: 'null'
description: Symmetry data for this material.
material_id:
anyOf:
- type: string
pattern: ^([A-Za-z]+-)?(\d+)(-[A-Za-z0-9]+)*$
examples:
- mp-3534
- '3453'
- mp-834-Ag
- type: string
examples:
- mp-ft
- task:pqrs
- type: 'null'
title: Material Id
description: 'The Materials Project ID of the material, used as a universal reference across property documents.This comes in the form: mp-******.'
deprecated:
type: boolean
title: Deprecated
description: Whether this property document is deprecated.
default: true
deprecation_reasons:
anyOf:
- items:
type: string
type: array
- type: 'null'
title: Deprecation Reasons
description: List of deprecation tags detailing why this document isn't valid.
last_updated:
type: string
format: date-time
title: Last Updated
description: Timestamp for the most recent calculation update for this property.
origins:
anyOf:
- items:
$ref: '#/components/schemas/PropertyOrigin'
type: array
- type: 'null'
title: Origins
description: Dictionary for tracking the provenance of properties.
warnings:
items:
type: string
type: array
title: Warnings
description: Any warnings related to this property.
default: []
structure:
$ref: '#/components/schemas/TypedStructureDict'
title: Structure
description: The structure used in the generation of the oxidation state data.
property_name:
type: string
title: Property Name
default: oxidation
possible_species:
items:
type: string
type: array
title: Possible Species
description: Possible charged species in this material.
possible_valences:
items:
type: number
type: array
title: Possible Valences
description: List of valences for each site in this material.
average_oxidation_states:
additionalProperties:
type: number
type: object
title: Average Oxidation States
description: Average oxidation states for each unique species.
method:
anyOf:
- type: string
- type: 'null'
title: Method
description: Method used to compute oxidation states.
type: object
required:
- structure
- possible_species
- possible_valences
- average_oxidation_states
title: OxidationStateDoc
description: Oxidation states computed from the structure
PropertyOrigin:
properties:
name:
type: string
title: Name
description: The property name
task_id:
anyOf:
- type: string
pattern: ^([A-Za-z]+-)?(\d+)(-[A-Za-z0-9]+)*$
examples:
- mp-3534
- '3453'
- mp-834-Ag
- type: string
examples:
- mp-ft
- task:pqrs
title: Task Id
description: The calculation ID this property comes from.
last_updated:
type: string
format: date-time
title: Last Updated
description: The timestamp when this calculation was last updated
type: object
required:
- name
- task_id
title: PropertyOrigin
description: Provenance document for the origin of properties in a material document
TypedStructureDict:
properties:
'@module':
type: string
title: '@Module'
'@class':
type: string
title: '@Class'
charge:
anyOf:
- type: number
- type: 'null'
title: Charge
lattice:
$ref: '#/components/schemas/TypedLatticeDict'
sites:
items:
$ref: '#/components/schemas/TypedSiteDict'
type: array
title: Sites
properties:
anyOf:
- $ref: '#/components/schemas/TypedAggregateProperitesDict'
- type: 'null'
type: object
required:
- '@module'
- '@class'
- lattice
- sites
title: TypedStructureDict
EmmetMeta:
properties:
emmet_version:
anyOf:
- type: string
- type: 'null'
title: Emmet Version
description: The version of emmet this document was built with.
default: 0.86.4rc4
pymatgen_version:
anyOf:
- type: string
- type: 'null'
title: Pymatgen Version
description: The version of pymatgen this document was built with.
default: 2026.4.16
run_id:
anyOf:
- type: string
- type: 'null'
title: Run Id
description: The run id associated with this data build.
batch_id:
anyOf:
- type: string
- type: 'null'
title: Batch Id
description: Identifier corresponding to the origin of this document's blessed task.
database_version:
anyOf:
- type: string
- type: 'null'
title: Database Version
description: The database version for the built data.
build_date:
anyOf:
- type: string
format: date-time
- type: 'null'
title: Build Date
description: The build date for this document.
license:
anyOf:
- type: string
enum:
- BY-C
- BY-NC
- type: 'null'
title: License
description: License for the data entry.
type: object
title: EmmetMeta
description: Default emmet metadata.
TypedSiteProperitesDict:
properties:
magmom:
anyOf:
- type: number
- type: 'null'
title: Magmom
charge:
anyOf:
- type: number
- type: 'null'
title: Charge
velocities:
anyOf:
- prefixItems:
- type: number
- type: number
- type: number
type: array
maxItems: 3
minItems: 3
- type: 'null'
title: Velocities
selective_dynamics:
anyOf:
- prefixItems:
- type: boolean
- type: boolean
- type: boolean
type: array
maxItems: 3
minItems: 3
- type: 'null'
title: Selective Dynamics
coordination_no:
anyOf:
- type: integer
- type: 'null'
title: Coordination No
forces:
anyOf:
- items:
type: number
type: array
- type: 'null'
title: Forces
type: object
title: TypedSiteProperitesDict
HTTPValidationError:
properties:
detail:
items:
$ref: '#/components/schemas/ValidationError'
type: array
title: Detail
type: object
title: HTTPValidationError
TypedSiteDict:
properties:
label:
anyOf:
- type: string
- type: 'null'
title: Label
name:
anyOf:
- type: string
- type: 'null'
title: Name
properties:
anyOf:
- $ref: '#/components/schemas/TypedSiteProperitesDict'
- type: 'null'
species:
anyOf:
- items:
$ref: '#/components/schemas/TypedSpeciesDict'
type: array
- type: 'null'
title: Species
abc:
anyOf:
- items:
type: number
type: array
- type: 'null'
title: Abc
xyz:
anyOf:
- items:
type: number
type: array
- type: 'null'
title: Xyz
type: object
title: TypedSiteDict
TypedAggregateProperitesDict:
properties:
magmom:
anyOf:
- items:
type: number
type: array
- type: 'null'
title: Magmom
charge:
anyOf:
- items:
type: number
type: array
- type: 'null'
title: Charge
velocities:
anyOf:
- items:
prefixItems:
- type: number
- type: number
- type: number
type: array
maxItems: 3
minItems: 3
type: array
- type: 'null'
title: Velocities
selective_dynamics:
anyOf:
- items:
prefixItems:
- type: boolean
- type: boolean
- type: boolean
type: array
maxItems: 3
minItems: 3
type: array
- type: 'null'
title: Selective Dynamics
type: object
title: TypedAggregateProperitesDict
TypedLatticeDict:
properties:
matrix:
items:
items:
type: number
type: array
type: array
title: Matrix
pbc:
anyOf:
- prefixItems:
- type: boolean
- type: boolean
- type: boolean
type: array
maxItems: 3
minItems: 3
- type: 'null'
title: Pbc
a:
type: number
title: A
b:
type: number
title: B
c:
type: number
title: C
alpha:
type: number
title: Alpha
beta:
type: number
title: Beta
gamma:
type: number
title: Gamma
volume:
type: number
title: Volume
type: object
required:
- matrix
- a
- b
- c
- alpha
- beta
- gamma
- volume
title: TypedLatticeDict
Response_OxidationStateDoc_:
properties:
data:
anyOf:
- items:
$ref: '#/components/schemas/OxidationStateDoc'
type: array
- type: 'null'
title: Data
description: List of returned data
errors:
anyOf:
- items:
$ref: '#/components/schemas/Error'
type: array
- type: 'null'
title: Errors
description: Any errors on processing this query
meta:
anyOf:
- $ref: '#/components/schemas/Meta'
- type: 'null'
description: Extra information for the query
type: object
title: Response[OxidationStateDoc]
Meta:
properties:
api_version:
type: string
title: Api Version
description: A string containing the version of the Materials API implementation, e.g. v0.9.5
default: 0.86.4rc5.dev1+g77c2c1315
time_stamp:
type: string
format: date-time
title: Time Stamp
description: A string containing the date and time at which the query was executed
total_doc:
anyOf:
- type: integer
minimum: 0.0
- type: 'null'
title: Total Doc
description: The total number of documents available for this query
facet:
anyOf:
- additionalProperties: true
type: object
- type: 'null'
title: Facet
description: A dictionary containing the facets available for this query
additionalProperties: true
type: object
title: Meta
description: Meta information for the MAPI Response.
Error:
properties:
code:
type: integer
title: Code
description: The error code
message:
type: string
title: Message
description: The description of the error
type: object
required:
- code
- message
title: Error
description: Base Error model for General API.
SymmetryData:
properties:
crystal_system:
anyOf:
- type: string
- type: 'null'
title: Crystal System
description: The crystal system for this lattice.
symbol:
anyOf:
- type: string
- type: 'null'
title: Space Group Symbol
description: The spacegroup symbol for the lattice.
hall:
anyOf:
- type: string
- type: 'null'
title: Hall Symbol
description: Hall symbol for the lattice
number:
anyOf:
- type: integer
- type: 'null'
title: Space Group Number
description: The spacegroup number for the lattice.
point_group:
anyOf:
- type: string
- type: 'null'
title: Point Group Symbol
description: The point group for the lattice.
symprec:
anyOf:
- type: number
- type: 'null'
title: Symmetry Finding Precision
description: The precision provided to spglib to determine the symmetry of this structure.
angle_tolerance:
anyOf:
- type: number
- type: 'null'
title: Angle Tolerance
description: Angle tolerance provided to spglib to determine the symmetry of this structure.
version:
anyOf:
- type: string
- type: 'null'
title: spglib version
type: object
title: SymmetryData
description: Defines a symmetry data set for materials documents
ValidationError:
properties:
loc:
items:
anyOf:
- type: string
- type: integer
type: array
title: Location
msg:
type: string
title: Message
type:
type: string
title: Error Type
input:
title: Input
ctx:
type: object
title: Context
type: object
required:
- loc
- msg
- type
title: ValidationError
TypedSpeciesDict:
properties:
element:
anyOf:
- type: string
- type: 'null'
title: Element
oxidation_state:
anyOf:
- type: number
- type: 'null'
title: Oxidation State
spin:
anyOf:
- type: number
- type: 'null'
title: Spin
occu:
anyOf:
- type: number
- type: 'null'
title: Occu
type: object
title: TypedSpeciesDict
securitySchemes:
ApiKeyAuth:
descriptions: MP API key to authorize requests
name: X-API-KEY
in: header
type: apiKey