Semiconducting Materials from Analogy and Chemical Theory

View the code on Github here.

Introduction

smact is a collection of tools and examples for “low-fi” screening of potential semiconducting materials through the use of chemical rules.

smact uses a combination of heuristics and models derived from data to rapidly search large areas of chemical space. This combination of methods allows smact to identify new materials for applications such as photovoltaics, water splitting and thermoelectrics.

Features of smact include:

• Chemical elements with associated properties

• Filters for oxidation states and charge balancing

• Structure prediction from chemical composition

• Composition probability prediction

• Property prediction from composition using pre-trained ROOST models

Install

The package is available via pip install smact.

License and citation

smact is distributed under an MIT license.

To cite the theory of smact please use:

• Computational screening of all stoichiometric inorganic materials

To cite the code of smact please use:

• SMACT: Semiconducting Materials by Analogy and Chemical Theory

Contents:

• Introduction
• Install
• License and citation
• Studies using smact
• Getting Started
  • Requirements
  • Installation
• Examples
  • Using element and species classes
  • Using filter
  • Using validity
    • Mixed-Valence Compounds
  • Building lists
  • Using oxidation states
    • Getting started with the oxidation_states submodule
  • Using compound electronegativity
  • Using the valence electron concentration
  • Using doper
    • Alternative metrics
  • Using distorter
  • Using the metallicity module
    • Key Changes
      • 1. Module: smact.metallicity
      • 2. Enhanced smact_validity
      • 3. Comprehensive Analysis Example
    • Machine Learning Classification
    • Future Development Directions
    • Contributing
    • References
  • Predicting Properties from Composition
    • Prerequisites
    • 1. Quick start — predict_band_gap
    • 2. Using RoostPropertyPredictor
    • 3. Uncertainty quantification
    • 4. Querying the model registry
    • 5. Combining with SMACT screening
    • Notes
• Tutorials
  • Quaternary oxide composition generation
    • Prerequisites
    • Workflow
      • 1. Import required libraries
      • 2. Define elements and combinations
      • 3. Define SMACT filtering function
      • 4. Process element combinations
      • 5. Generate pretty formulas
      • 6. Create DataFrame and add descriptors
      • 7. Save results to a CSV file
  • Reproducing results
  • Filtering a search space using oxidation states
    • Composition generation
    • Applying the oxidation states model
      • Visualising the compound probabilities of the SMACT generated compositions.
  • Metal vs. Non-Metal Classification on matbench_expt_is_metal
    • Using Metallicity Features + XGBoost + Threshold Tuning
    • 1. Loading the full matbench_expt_is_metal dataset
    • 2. Feature extraction - Intermetallic descriptors
    • 3. Model + Cross-validation + Threshold tuning
    • 4. Hyperparameter/Threshold search with cross-validation
    • 5. Retrain best model on full training set & evaluate
    • 6. SHAP feature analysis
  • Testing charge-neutrality of the compositions in the GNoME database
    • Plotting the results
    • Conclusion
  • Crystal Structure Prediction via Ionic Substitutions
    • 1. Getting Started
    • 2. Introducing the Structure Prediction Module
      • The SmactStructure class
      • The CationMutator class
      • The StructureDB class
      • The StructurePredictor class
    • 2. Next Steps
  • Exploring crystal space
    • 1. Getting started
    • 2. Generating compositions
      • Key parameters:
    • 3. Download data from the Materials Project
      • Key parameters:
    • 4. Categorise compositions
  • Next steps
  • Visualising crystal space
    • 1. Element embeddings
    • 2. Dimension reduction
    • 3. Visualisation of the low dimensional embeddings
  • Creating oxidation states lists
    • 1. Getting started
    • 2. Using the oxidation states filter
      • Writing the filtered oxidation states to a file
    • Using custom Oxidation States in SMACT workflows
      • SMACT Filter
      • SMACT Validity
• smact Python package
  • Element
    • Element.AtomicWeight
    • Element.HHI_p
    • Element.HHI_r
    • Element.MeltingT
    • Element.SSE
    • Element.SSEPauling
    • Element.atomic_weight
    • Element.coord_envs
    • Element.covalent_radius
    • Element.crustal_abundance
    • Element.dipol
    • Element.e_affinity
    • Element.eig
    • Element.eig_s
    • Element.hhi_p
    • Element.hhi_r
    • Element.ionpot
    • Element.mass
    • Element.melting_t
    • Element.mendeleev
    • Element.name
    • Element.num_valence
    • Element.num_valence_modified
    • Element.number
    • Element.oxidation_states
    • Element.oxidation_states_custom
    • Element.oxidation_states_icsd16
    • Element.oxidation_states_icsd24
    • Element.oxidation_states_smact14
    • Element.oxidation_states_sp
    • Element.oxidation_states_wiki
    • Element.pauling_eneg
    • Element.sse
    • Element.sse_pauling
    • Element.symbol
  • Species
  • are_eq()
  • element_dictionary()
  • lattices_are_same()
  • neutral_ratios()
  • neutral_ratios_iter()
  • ordered_elements()
  • Submodules
    • smact.property_prediction module
      • Installation
      • Architecture
      • Available Models
      • Model Versioning and Fidelity
      • Model Resolution Order
      • Model Management
      • Training New Models
      • References
      • Submodules
    • smact.structure_prediction module
      • Submodules
    • smact.dopant_prediction module
      • Submodules
    • smact.utils module
      • Submodules
    • smact.properties module
      • band_gap_Harrison()
      • compound_electroneg()
      • eneg_mulliken()
      • valence_electron_count()
    • smact.screening module
      • ICSD24FilterConfig
      • SmactFilterOutputs
      • eneg_states_test()
      • eneg_states_test_threshold()
      • ml_rep_generator()
      • pauling_test()
      • smact_filter()
      • smact_validity()
    • smact.oxidation_states module
      • OxidationStateProbabilityFinder
    • smact.metallicity module
      • get_d_block_element_fraction()
      • get_distinct_metal_count()
      • get_element_fraction()
      • get_metal_fraction()
      • get_pauling_test_mismatch()
      • metallicity_score()
    • smact.builder module
      • cubic_perovskite()
      • wurtzite()
    • smact.distorter module
      • build_sub_lattice()
      • get_inequivalent_sites()
      • get_sg()
      • make_substitution()
    • smact.lattice module
      • Lattice
      • Site
    • smact.lattice_parameters module
      • b10()
      • b2()
      • bcc()
      • bct()
      • cubic_perovskite()
      • diamond()
      • fcc()
      • hcp()
      • rocksalt()
      • stuffed_wurtzite()
      • wurtzite()
      • zincblende()
    • smact.data_loader module
      • float_or_None()
      • lookup_element_data()
      • lookup_element_hhis()
      • lookup_element_magpie_data()
      • lookup_element_oxidation_states()
      • lookup_element_oxidation_states_custom()
      • lookup_element_oxidation_states_icsd()
      • lookup_element_oxidation_states_icsd24()
      • lookup_element_oxidation_states_sp()
      • lookup_element_oxidation_states_wiki()
      • lookup_element_shannon_radius_data()
      • lookup_element_shannon_radius_data_extendedML()
      • lookup_element_sse2015_data()
      • lookup_element_sse_data()
      • lookup_element_sse_pauling_data()
      • lookup_element_valence_data()
• Changelog
  • v4.0.0 (2026-03-03)
  • v3.2.0 (2025-07-31)
  • v3.1.0 (2025-04-02)
  • v3.0.2 (2025-01-13)
  • v3.0.1 (2024-12-18)
  • v3.0 (2024-12-02)
  • v2.8 (2024-09-26)
  • v2.7 (2024-08-30)
  • v2.6 (2024-07-10)
  • v2.5.5 (2023-12-07)
  • v2.5.4 (2023-11-30)
  • v2.5.3 (2023-08-23)
  • v2.5.2 (2023-07-14)
  • v2.5.1 (2023-05-02)
  • v2.5.0 (2022-12-22)
  • v2.4.2 (2022-12-14)
  • v2.4.1 (2022-09-22)
  • v2.4.0 (2022-09-20)
  • v2.3.3.1 (2022-07-07)
  • v2.3.3 (2022-07-07)
  • v2.3.2 (2022-06-09)
  • v2.3.1 (2021-11-04)
  • v2.3 (2021-10-06)
  • v2.2 (2019-11-06)
  • v2.1 (2019-06-10)
  • v2.0.2 (2019-03-20)
  • v2.0.1 (2019-03-13)
  • v1.2 (2017-01-06)
  • v1.01 (2016-09-12)
  • v1.0 (2016-04-29)

Indices and tables

• Index

• Module Index

• Search Page