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Special Quasirandom Structures

Optional dependency

SqsGenerator requires the sqsgen extra.

uv add "materialsframework[sqsgen]"

pip install "materialsframework[sqsgen]"

Generates a finite supercell whose short-range order mimics that of a truly random substitutional alloy, so disordered-alloy properties can be modeled with a small, deterministic cell instead of a much larger explicitly-disordered one.

from materialsframework.tools.sqsgen import SqsGenerator

sqs = SqsGenerator(iterations=5000, mode="random")
result = sqs.generate(composition="Fe0.5Ni0.5", crystal_structure="BCC", supercell_size=(4, 4, 4))

structure = result["structure"]   # pymatgen Structure
print(result["objective"])        # final SQS objective value (0 = exact match to random target)

See Theory for the derivation, or the API Reference for the full parameter list.