get_elastic_properties

Instructions

Get elastic and mechanical properties for a material.

Args:
    material_id: Materials Project ID (e.g., "mp-149" for Silicon)

Returns:
    JSON with elastic properties including bulk modulus, shear modulus,
    Young's modulus, Poisson's ratio, and elastic tensor

Implementation Reference

• src/mcp_materials/server.py:547-623 (handler)

  The core handler function for the 'get_elastic_properties' tool. Decorated with @mcp.tool() for automatic registration and schema inference from signature/docstring. Fetches elasticity data from Materials Project API via MPRester.materials.elasticity.search and extracts key mechanical properties like moduli and Poisson's ratio.

  @mcp.tool()
  def get_elastic_properties(
      material_id: str,
  ) -> str:
      """
      Get elastic and mechanical properties for a material.
  
      Args:
          material_id: Materials Project ID (e.g., "mp-149" for Silicon)
  
      Returns:
          JSON with elastic properties including bulk modulus, shear modulus,
          Young's modulus, Poisson's ratio, and elastic tensor
      """
      has_key, key_or_error = check_api_key()
      if not has_key:
          return json.dumps({"error": key_or_error})
  
      try:
          from mp_api.client import MPRester
  
          with MPRester(key_or_error) as mpr:
              # Get elasticity data
              docs = mpr.materials.elasticity.search(
                  material_ids=[material_id],
              )
  
              if not docs:
                  return json.dumps({
                      "material_id": material_id,
                      "error": "No elastic data available for this material",
                      "note": "Elastic properties are only computed for a subset of materials",
                  })
  
              doc = docs[0]
  
              # Extract elastic properties
              properties = {
                  "material_id": material_id,
                  "formula": doc.formula_pretty if hasattr(doc, 'formula_pretty') else None,
  
                  # Voigt-Reuss-Hill averages (most commonly used)
                  "bulk_modulus_vrh_GPa": doc.bulk_modulus.vrh if doc.bulk_modulus else None,
                  "shear_modulus_vrh_GPa": doc.shear_modulus.vrh if doc.shear_modulus else None,
                  "youngs_modulus_GPa": doc.young_modulus if hasattr(doc, 'young_modulus') else None,
                  "poisson_ratio": doc.homogeneous_poisson if hasattr(doc, 'homogeneous_poisson') else None,
  
                  # Voigt bounds (upper)
                  "bulk_modulus_voigt_GPa": doc.bulk_modulus.voigt if doc.bulk_modulus else None,
                  "shear_modulus_voigt_GPa": doc.shear_modulus.voigt if doc.shear_modulus else None,
  
                  # Reuss bounds (lower)
                  "bulk_modulus_reuss_GPa": doc.bulk_modulus.reuss if doc.bulk_modulus else None,
                  "shear_modulus_reuss_GPa": doc.shear_modulus.reuss if doc.shear_modulus else None,
  
                  # Derived properties
                  "universal_anisotropy": doc.universal_anisotropy if hasattr(doc, 'universal_anisotropy') else None,
                  "debye_temperature_K": doc.debye_temperature if hasattr(doc, 'debye_temperature') else None,
  
                  # Classification - convert enum to string
                  "state": str(doc.state.value) if hasattr(doc, 'state') and hasattr(doc.state, 'value') else (str(doc.state) if hasattr(doc, 'state') else None),
              }
  
              # Add elastic tensor if available (6x6 Voigt notation)
              if hasattr(doc, 'elastic_tensor') and doc.elastic_tensor:
                  tensor = doc.elastic_tensor
                  if hasattr(tensor, 'ieee_format'):
                      properties["elastic_tensor_GPa"] = tensor.ieee_format
                  elif hasattr(tensor, 'raw'):
                      properties["elastic_tensor_GPa"] = tensor.raw
  
              return json.dumps(properties, indent=2)
  
      except Exception as e:
          return json.dumps({"error": str(e)})