MCP Materials Server

Instructions

Implementation Reference

• src/mcp_materials/server.py:547-622 (handler)

  The handler function implementing the get_elastic_properties tool. It queries the Materials Project API for elastic properties of a given material_id, extracts key moduli (bulk, shear, Young's, Poisson's ratio), bounds, and elastic tensor if available, returning formatted JSON. Also handles API key checks and errors. The @mcp.tool() decorator registers it as an MCP tool.
  @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)})