The Elementary Multiperspective Material Ontology (EMMO)

The Elementary Multiperspective Material Ontology (EMMO) is a foundational ontology developed by the European Materials Modelling Council (EMMC) to provide a standard representational framework for materials science and engineering. EMMO is unique in that it starts from the bottom level, using the physical world as described by applied sciences, especially physics and materials science, rather than from abstract upper-level concepts. The ontology covers a wide range of concepts including materials, processes, properties, structures, and measurement techniques, supporting the semantic integration of materials modelling, characterization, and experimental data. EMMO is modular and extensible, enabling domain-specific extensions for specialized applications in materials research, digital twins, and manufacturing. By providing a rigorous semantic foundation, EMMO facilitates data interoperability, knowledge sharing, and advanced analytics across the materials science community. The ontology is actively maintained and extended to incorporate new concepts and requirements from ongoing research and industrial projects.

Example Usage: Annotate a materials database with EMMO terms to describe the composition, structure, and properties of a material sample, the experimental techniques used for characterization, and the modelling workflows applied, enabling semantic search and data integration across research projects.

Metrics & Statistics

Graph Statistics

Total Nodes

13613

Total Edges

30349

Root Nodes

281

Leaf Nodes

7742
Knowledge Coverage Statistics

Classes

2448

Individuals

2

Properties

181
Hierarchical Metrics

Maximum Depth

41

Minimum Depth

0

Average Depth

8.16

Depth Variance

107.87
Breadth Metrics

Maximum Breadth

552

Minimum Breadth

1

Average Breadth

67.24

Breadth Variance

14619.32
LLMs4OL Dataset Statistics

Term Types

2

Taxonomic Relations

16281

Non-taxonomic Relations

52

Average Terms per Type

2.00

Usage Example

Use the following code to import this ontology programmatically:

from ontolearner.ontology import EMMO

ontology = EMMO()
ontology.load("path/to/EMMO-ontology.owl")

# Extract datasets
data = ontology.extract()

# Access specific relations
term_types = data.term_typings
taxonomic_relations = data.type_taxonomies
non_taxonomic_relations = data.type_non_taxonomic_relations