Input Keys Reference

Magesty.jl uses TOML configuration files. Below is an annotated example for a BCC Fe supercell, followed by a full reference for every supported key.

Annotated Example

[general]
name = "bccfe"
kd   = ["Fe"]           # list of element names
nat  = 16               # total number of atoms in the supercell
periodicity = [true, true, true]  # apply periodic boundary to all (x, y, z) directions

[symmetry]
tolerance = 1e-5        # symmetry detection tolerance (optional, default 1e-3)
isotropy = true

[interaction]
nbody = 2               # maximum interaction body
[interaction.body1]
lmax.Fe = 0             # 1-body maximum angular momentum per element, i.e. this represents on-site anisotropy
[interaction.body2]
lsum = 2                # cutoff summation of l values for basis functions
cutoff."Fe-Fe" = -1     # pairwise cutoff radius in Å (-1 uses all possible pairs)

[regression]
datafile = "EMBSET" # path to training data
weight   = 0.5          # 0 = torque only, 1 = energy only, 0.5 = balanced
alpha    = 0.0          # elastic-net mixing (0 = ridge)
lambda   = 0.0          # regularization strength (0 = no regularization)

[structure]
kd_list  = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]  # element index per atom
lattice  = [            # lattice parameters
  [5.66, 0.0, 0.0],
  [0.0, 5.66, 0.0],
  [0.0, 0.0, 5.66],
]
position = [            # fractional coordinates
  [0.00, 0.00, 0.00],
  [0.25, 0.25, 0.25],
  [0.00, 0.00, 0.50],
  [0.50, 0.00, 0.00],
  [0.00, 0.50, 0.00],
  [0.25, 0.25, 0.75],
  [0.75, 0.25, 0.25],
  [0.25, 0.75, 0.25],
  [0.00, 0.50, 0.50],
  [0.50, 0.00, 0.50],
  [0.50, 0.50, 0.00],
  [0.25, 0.75, 0.75],
  [0.75, 0.25, 0.75],
  [0.75, 0.75, 0.25],
  [0.50, 0.50, 0.50],
  [0.75, 0.75, 0.75],
]

Key Reference

`[general]`

Key	Type	Required	Description
`name`	String	yes	System name
`kd`	Vector{String}	yes	Element names
`nat`	Int	yes	Number of atoms in supercell
`periodicity`	Vector{Bool}	no	Periodic boundary conditions (default: `[true,true,true]`)

`[symmetry]`

Key	Type	Required	Description
`tolerance`	Float64	no	Symmetry detection tolerance (default: `1e-3`)
`isotropy`	Bool	no	Only include isotropic (L=0) terms (default: `false`)

`[interaction]`

Key	Type	Required	Description
`nbody`	Int	yes	Maximum interaction order
`body1.lmax.<elem>`	Int	no	On-site max angular momentum per element
`body<n>.lsum`	Int	yes (n≥2)	Max L sum for n-body basis
`body<n>.cutoff."<e1>-<e2>"`	Float64	yes (n≥2)	Pairwise cutoff radius in Å

`[regression]`

Key	Type	Required	Description
`datafile`	String	yes	Path to EMBSET training data
`ndata`	Int	no	Number of data points to use (default: `-1` = all)
`weight`	Float64	no	Energy/torque balance: 0=torque only, 1=energy only (default: `0.0`)
`alpha`	Float64	no	Elastic-net mixing parameter (default: `0.0`)
`lambda`	Float64	no	Regularization strength (default: `0.0`)

`[structure]`

Key	Type	Required	Description
`kd_list`	Vector{Int}	yes	Element index (1-based, into `kd`) per atom
`lattice`	3×3 Float64	yes	Lattice vectors in Å; each of the three rows in the TOML array defines one lattice vector (a₁, a₂, a₃)
`position`	Vector of 3-vectors	yes	Fractional atomic coordinates