Family files

A family file is YAML with these keys. meidnet families NAME prints a summary and the constraints with their explanations; errors name the offending key or element.

key	required	meaning
name, title, description	name	identification; description appears in the Studio
prototype.lattice	yes	cubic, fcc_primitive, bcc_primitive, or explicit a, b, c, alpha, beta, gamma
prototype.reference_a		typical cubic cell edge (Å), used by the cubic_cell search term
prototype.sites[]	yes	{group, frac} in decoder slot order; fractional coordinates
groups.<G>.description		sentence shown in reports
groups.<G>.elements	yes	every element the group may hold (all variants)
groups.<G>.sample		subset offered to the final element choice (default: elements)
groups.<G>.oxidation_states		{element: [charges]} used for charge balance and neutrality bias
sampling_order		order in which groups are chosen; the last is restricted to charge-balancing elements
lattice.rule		bond_sum (a = factor × Σ r_ionic of groups, clipped to min..max) or fixed
variants.<V>.groups		per-variant elements, sample, oxidation_states of any group
variants.<V>.params		{rule_or_term_name: {param: value}} applied to search terms and constraints
require_variant		default true: a variant must be chosen when variants exist
search_terms[]		{name, …params} soft penalties during the latent search
logit_transforms[]		{name, …params} edits of the decoder's element scores (e.g. neutrality_bias)
constraints[]		{name, …params} hard rules; min_distance runs before symmetry refinement, the rest after
refine_symmetry, symprec		run spglib refinement on candidates (default true, 0.05)

User-side changes without editing the file: generation.variant, exclude_elements, only_elements, overrides ({name: {param: value}} for any search term or constraint).

The built-in files are the complete reference: perovskite_abx3.yaml, double_perovskite_a2bbx6.yaml.