{"artifact_id":"L1-519","layer":"L1","title":"X-ray Diffraction Crystal Space-Group Classification (PWDR)","domain":"Materials Science","sub_domain":"Crystal symmetry classification from XRD lattice + structure-factor recovery","physics_fingerprint":{"L_DAG":6.8,"title":"X-ray Diffraction Crystal Space-Group Classification (PWDR)","domain":"Materials Science","carrier":"x_ray","primitives":["L.xray_source","L.bragg_diffraction","L.structure_factor","L.lattice_parameter_recovery","L.systematic_absence_test","L.space_group_decision_tree","int.angular"],"sub_domain":"Crystal symmetry classification from XRD lattice + structure-factor recovery","noise_model":"poisson","problem_class":"linear_inverse_with_categorical_readout","solution_space":"1D_space_group_label","difficulty_delta":5,"integration_axis":"angular_spatial","sensing_mechanism":"bragg_diffraction_with_space_group_classifier"},"observable_profile":{"metric":"categorical_accuracy","regime":"Existence and uniqueness inherited from L1-518 with additional constraint: pseudosymmetry can cause space-group ambiguity (e.g., P2_1/n vs Pn — distinguishing requires additional statistics or chemistry constraint). Stability inherits L1-518's high condition number plus additive systematic_absence_threshold_uncertainty. Joint Hadamard well-posedness for the space-group classification established by Hahn 2005 (International Tables Vol A), Cromer-Liberman 1970 (anomalous scattering for centrosymmetry tests), Le Bail 2005 (powder indexing), Kabsch 2010 (XDS for space-group determination), Spek 2003 (PLATON ADDSYM).","secondary":"top_3_accuracy"},"size_tiers":{"center_spec":{"omega":{"two_theta_max":120,"two_theta_min":5,"two_theta_step":0.02,"lambda_angstrom":1.5418,"twinning_artifact":0.0,"instrumental_broadening":0.05,"pseudosymmetry_ambiguity":0.0,"modulation_or_superlattice":0.0,"lattice_parameter_uncertainty":0.0,"systematic_absence_threshold_uncertainty":0.0},"input_format":"powder_xrd_pattern_with_space_group_label","problem_class":"xrd_space_group_pwdr","forward_operator":"xrd_space_group_pwdr_forward","epsilon_fn_center":"0.85_accuracy"},"omega_bounds":{"two_theta_max":[60,160],"two_theta_min":[1,30],"lambda_angstrom":[0.4,2.5],"instrumental_broadening":[0.01,0.5]},"epsilon_bounds":{"categorical_accuracy":[0.3,0.99]},"allowed_problem_classes":["xrd_space_group_pwdr","xrd_crystal_system_pwdr","xrd_bravais_pwdr","xrd_point_group_pwdr","xrd_centrosymmetry_pwdr"],"allowed_omega_dimensions":["lambda_angstrom","two_theta_min","two_theta_max","two_theta_step","instrumental_broadening","lattice_parameter_uncertainty","systematic_absence_threshold_uncertainty","twinning_artifact","modulation_or_superlattice","pseudosymmetry_ambiguity"],"allowed_forward_operators":["xrd_space_group_pwdr_forward","xrd_crystal_system_pwdr_forward","xrd_bravais_pwdr_forward","xrd_point_group_pwdr_forward"]},"hardness_fn":{"type":"epsilon_fn","delta":5,"kappa":600,"metric":"categorical_accuracy"},"initiator_dataset":[{"name":"primary","weight":1.0,"ipfs_cid":null,"license_hash":null}],"status":"testnet","staked_pwm":0.0,"chain_hash":"0xeecb4fc500389a8009bfab9a6b2e0ddb83b0b17ed2ade9f3f25506d88e0d71a7","chain_tx_hash":"0xecefcf2feafe0b852896a9ab692100199979b48b3c591987bb3aa9d43b794dda","chain_block":41554142}