Materials Project Materials XAS API

Route providing computed x-ray absorption spectroscopy data for a material following the methodology discussed by [Mathew *et al.*](https://doi.org/10.1038/sdata.2018.151) and [Chen *et al.*](https://doi.org/10.1038/s41597-021-00936-5) Note that x-ray absorption spectroscopy data has not been calculated for all materials in the Materials Project database. See the `XASDoc` schema for a full list of fields returned by this route.

OpenAPI Specification

materials-project-materials-xas-api-openapi.yml Raw ↑
openapi: 3.1.0
info:
  title: Materials Project Defect Tasks Materials XAS API
  description: "\nThe Materials Project API allows anyone to have direct access to current, up-to-date information from the Materials Project database in a structured way.\n\nThis allows for analysis, development of automated tools, machine learning, downloading personal copies of the Materials Project database and more on a large scale.\n\nThe API is offered with the hopes of making Materials Project data more useful to you. We want you to use our data! As such, the API is offered free-of-charge and we support several tools to help you get started.\n\n## API Key\nTo make any request to the Materials Project API, you must use an API key. Your API key is generated for you automatically upon registering with the Materials Project website and is synced with the email you used to register.\n\nRemember to keep your API key safe and to not share it with anyone you do not trust.\n\nIf you are logged in, you can always access your API key from this page or from your [dashboard](https://next-gen.materialsproject.org/dashboard).\n\nIf you intend heavy API usage, you can give us a heads up by sending a message to <heavy.api.use@materialsproject.org>. With the exception of retrieving charge densities, this is not required, but may help us if we see unusual load on our servers.\n\n## Accessing Data\nTo use the API, you have three options:\n\n1. You can use our first-party supported Python client. This is the recommend route. The `mp-api` package containing the client is pip installable.\n\n    ```\n    pip install mp-api\n    ```\n\n    The `MPRester` client can be accessed by importing from it. This will ultimately replace the legacy `MPRester` available in pymatgen.\n\n    For more details on how to use this, including code examples, please see <https://next-gen.materialsproject.org/api>.\n\n2. You can demo the API interactively on this documentation page. Click the \"Authorize\" button, paste in your API key, and then click the appropriate section to try out a query.\n\n3. Since this is a REST API, and offers a fully-compliant OpenAPI specification, it's possible to use the API with many libraries in many languages and environments, including JavaScript, MATLAB, Mathematica, etc. However, we do not offer first-party support for explaining how to do this, and you will have to follow the specification yourself.\n\n"
  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 XAS
  description: Route providing computed x-ray absorption spectroscopy data for a material following the             methodology discussed by [Mathew *et al.*](https://doi.org/10.1038/sdata.2018.151)             and [Chen *et al.*](https://doi.org/10.1038/s41597-021-00936-5)             Note that x-ray absorption spectroscopy data has not been calculated for all materials in the Materials             Project database. See the `XASDoc` schema for a full list of fields returned by this route.
paths:
  /materials/xas/:
    get:
      tags:
      - Materials XAS
      summary: Get XASDoc documents
      operationId: search_materials_xas__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: elements
        in: query
        required: false
        schema:
          anyOf:
          - type: string
            maxLength: 60
          - type: 'null'
          description: Query by elements in the material composition as a comma-separated list
          title: Elements
        description: Query by elements in the material composition as a comma-separated list
      - name: exclude_elements
        in: query
        required: false
        schema:
          anyOf:
          - type: string
            maxLength: 60
          - type: 'null'
          description: Query by excluded elements in the material composition as a comma-separated list
          title: Exclude Elements
        description: Query by excluded elements in the material composition as a comma-separated list
      - name: edge
        in: query
        required: false
        schema:
          type: string
          title: XAS Edge
      - name: spectrum_type
        in: query
        required: false
        schema:
          type: string
          title: Spectrum Type
      - name: absorbing_element
        in: query
        required: false
        schema:
          $ref: '#/components/schemas/Element'
          title: Absorbing Element
      - name: spectrum_ids
        in: query
        required: false
        schema:
          anyOf:
          - type: string
          - type: 'null'
          description: Comma-separated list of spectrum_id to query on
          title: Spectrum Ids
        description: Comma-separated list of spectrum_id to query on
      - 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 XASDoc 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` `spectrum_name` `material_id` `spectrum_id` `last_updated` `warnings` `spectrum` `task_ids` `absorbing_element` `spectrum_type` `edge`'
          title: ' Fields'
        description: 'Fields to project from XASDoc 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` `spectrum_name` `material_id` `spectrum_id` `last_updated` `warnings` `spectrum` `task_ids` `absorbing_element` `spectrum_type` `edge`'
      - name: _all_fields
        in: query
        required: false
        schema:
          type: boolean
          description: Include all fields.
          default: false
          title: ' All Fields'
        description: Include all fields.
      - name: _sort_fields
        in: query
        required: false
        schema:
          anyOf:
          - type: string
          - type: 'null'
          description: Comma delimited fields to sort with. Prefixing '-' to a field will force a sort in descending order.
          title: ' Sort Fields'
        description: Comma delimited fields to sort with. Prefixing '-' to a field will force a sort in descending order.
      responses:
        '200':
          description: Search for a XASDoc
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Response_XASDoc_'
        '422':
          description: Validation Error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HTTPValidationError'
components:
  schemas:
    TypedSiteProperitesDict:
      properties:
        magmom:
          anyOf:
          - type: number
          - type: 'null'
          title: Magmom
        charge:
          anyOf:
          - type: number
          - type: 'null'
          title: Charge
        velocities:
          anyOf:
          - prefixItems:
            - type: number
            - type: number
            - type: number
            type: array
            maxItems: 3
            minItems: 3
          - type: 'null'
          title: Velocities
        selective_dynamics:
          anyOf:
          - prefixItems:
            - type: boolean
            - type: boolean
            - type: boolean
            type: array
            maxItems: 3
            minItems: 3
          - type: 'null'
          title: Selective Dynamics
        coordination_no:
          anyOf:
          - type: integer
          - type: 'null'
          title: Coordination No
        forces:
          anyOf:
          - items:
              type: number
            type: array
          - type: 'null'
          title: Forces
      type: object
      title: TypedSiteProperitesDict
    XasSpectrumID:
      properties:
        identifier:
          anyOf:
          - type: string
            pattern: ^([A-Za-z]+-)?(\d+)(-[A-Za-z0-9]+)*$
            examples:
            - mp-3534
            - '3453'
            - mp-834-Ag
          - type: string
            examples:
            - mp-ft
            - task:pqrs
          title: Identifier
        suffix:
          prefixItems:
          - type: string
          - $ref: '#/components/schemas/Element'
          - type: string
          type: array
          maxItems: 3
          minItems: 3
          title: Suffix
        separator:
          type: string
          title: Separator
          default: '-'
      type: object
      required:
      - identifier
      - suffix
      title: XasSpectrumID
    TypedElementDict:
      properties:
        '@module':
          type: string
          title: '@Module'
        '@class':
          type: string
          title: '@Class'
        element:
          type: string
          title: Element
      type: object
      required:
      - '@module'
      - '@class'
      - element
      title: TypedElementDict
    XASDoc:
      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:
          - $ref: '#/components/schemas/SymmetryData'
          - type: 'null'
          description: Symmetry data for this material.
        spectrum_name:
          type: string
          title: Spectrum Name
          default: XAS
        material_id:
          anyOf:
          - type: string
            pattern: ^([A-Za-z]+-)?(\d+)(-[A-Za-z0-9]+)*$
            examples:
            - mp-3534
            - '3453'
            - mp-834-Ag
          - type: string
            examples:
            - mp-ft
            - task:pqrs
          - type: 'null'
          title: Material Id
          description: 'The ID of the material, used as a universal reference across proeprty documents. This comes in the form: mp-******.'
        spectrum_id:
          $ref: '#/components/schemas/XasSpectrumID'
        last_updated:
          type: string
          format: date-time
          title: Last Updated
          description: Timestamp for the most recent calculation update for this property.
        warnings:
          items:
            type: string
          type: array
          title: Warnings
          description: Any warnings related to this property.
          default: []
        spectrum:
          anyOf:
          - $ref: '#/components/schemas/TypedXASSpectrumDict'
          - type: 'null'
          title: Spectrum
          description: The XAS spectrum for this calculation.
        task_ids:
          anyOf:
          - items:
              type: string
            type: array
          - type: 'null'
          title: Calculation IDs
          description: List of Calculations IDs used to make this XAS spectrum.
        absorbing_element:
          type: string
          title: Absorbing Element
          description: Absoring element.
        spectrum_type:
          type: string
          title: Spectrum Type
          description: XAS spectrum type.
        edge:
          type: string
          title: Absorption Edge
          description: The interaction edge for XAS.
      type: object
      required:
      - spectrum_id
      - absorbing_element
      - spectrum_type
      - edge
      title: XASDoc
      description: Document describing a XAS Spectrum.
    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
    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
    Element:
      type: string
      enum:
      - H
      - D
      - T
      - He
      - Li
      - Be
      - B
      - C
      - N
      - O
      - F
      - Ne
      - Na
      - Mg
      - Al
      - Si
      - P
      - S
      - Cl
      - Ar
      - K
      - Ca
      - Sc
      - Ti
      - V
      - Cr
      - Mn
      - Fe
      - Co
      - Ni
      - Cu
      - Zn
      - Ga
      - Ge
      - As
      - Se
      - Br
      - Kr
      - Rb
      - Sr
      - Y
      - Zr
      - Nb
      - Mo
      - Tc
      - Ru
      - Rh
      - Pd
      - Ag
      - Cd
      - In
      - Sn
      - Sb
      - Te
      - I
      - Xe
      - Cs
      - Ba
      - La
      - Ce
      - Pr
      - Nd
      - Pm
      - Sm
      - Eu
      - Gd
      - Tb
      - Dy
      - Ho
      - Er
      - Tm
      - Yb
      - Lu
      - Hf
      - Ta
      - W
      - Re
      - Os
      - Ir
      - Pt
      - Au
      - Hg
      - Tl
      - Pb
      - Bi
      - Po
      - At
      - Rn
      - Fr
      - Ra
      - Ac
      - Th
      - Pa
      - U
      - Np
      - Pu
      - Am
      - Cm
      - Bk
      - Cf
      - Es
      - Fm
      - Md
      - 'No'
      - Lr
      - Rf
      - Db
      - Sg
      - Bh
      - Hs
      - Mt
      - Ds
      - Rg
      - Cn
      - Nh
      - Fl
      - Mc
      - Lv
      - Ts
      - Og
      title: Element
      description: Enum representing an element in the periodic table.
    TypedXASSpectrumDict:
      properties:
        '@module':
          type: string
          title: '@Module'
        '@class':
          type: string
          title: '@Class'
        '@version':
          type: string
          title: '@Version'
        x:
          items:
            type: number
          type: array
          title: X
        y:
          items:
            type: number
          type: array
          title: Y
        structure:
          $ref: '#/components/schemas/TypedStructureDict'
        absorbing_element:
          $ref: '#/components/schemas/TypedElementDict'
        edge:
          type: string
          title: Edge
        spectrum_type:
          type: string
          title: Spectrum Type
        absorbing_index:
          type: integer
          title: Absorbing Index
      type: object
      required:
      - '@module'
      - '@class'
      - '@version'
      - x
      - y
      - structure
      - absorbing_element
      - edge
      - spectrum_type
      - absorbing_index
      title: TypedXASSpectrumDict
    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
    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.
    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
    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
    Response_XASDoc_:
      properties:
        data:
          anyOf:
          - items:
              $ref: '#/components/schemas/XASDoc'
            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[XASDoc]
    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.
    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
    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.
    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
    HTTPValidationError:
      properties:
        detail:
          items:
            $ref: '#/components/schemas/ValidationError'
          type: array
          title: Detail
      type: object
      title: HTTPValidationError
  securitySchemes:
    ApiKeyAuth:
      descriptions: MP API key to authorize requests
      name: X-API-KEY
      in: header
      type: apiKey