Configuration

AmorphGen uses a nested dictionary for pipeline configuration. Default values are defined in default_config.py and can be overridden at runtime via CLI flags, YAML config files, or Python API.

Default configuration

amorphgen.configs.default_config

Central configuration for the melt-and-quench pipeline.

Override any value by passing cfg_override to MeltQuenchPipeline or to individual stage functions.

Configuration keys

Section	Key	Default	Description
top-level	`model`	`"mace-mpa-0"`	MLIP model name
top-level	`device`	`"auto"`	Compute device (`cpu`, `cuda`, `mps`)
top-level	`default_dtype`	`"float64"`	Precision (`float64` for opt, `float32` for MD)
`opt`	`fmax`	`0.01`	Force convergence (eV/A)
`opt`	`max_steps`	`1000`	Max optimisation steps
`opt`	`cell_filter`	`"FrechetCellFilter"`	Cell filter: FrechetCellFilter, UnitCellFilter, ExpCellFilter, StrainFilter, cubic, none
`melt`	`T_start`	`300`	Start temperature (K)
`melt`	`T_end`	`3000`	Melt temperature (K)
`melt`	`T_step`	`100`	Temperature step per segment (K)
`melt`	`rate`	`None`	Heating rate (K/ps), auto-calculates steps_per_T
`melt`	`steps_per_T`	`2000`	MD steps per temperature step
`melt`	`timestep`	`0.5`	MD timestep (fs)
`eq_premelt`	`T`	`300`	Pre-melt equilibration T (K)
`eq_premelt`	`steps`	`100000`	Pre-melt equilibration steps (50 ps)
`eq_high`	`T`	`3000`	High-T equilibration T (K)
`eq_high`	`steps`	`20000`	High-T equilibration steps (10 ps)
`quench`	`T_start`	`3000`	Quench start T (K)
`quench`	`T_end`	`300`	Quench end T (K)
`quench`	`T_step`	`-100`	Temperature step (K, negative for cooling)
`quench`	`steps_per_T`	`2000`	MD steps per temperature step
`quench`	`rate`	`None`	Cooling rate (K/ps), auto-calculates steps_per_T
`eq_low`	`T`	`300`	Low-T equilibration T (K)
`eq_low`	`steps`	`20000`	Low-T equilibration steps (10 ps)

Configuration precedence

CLI arguments > YAML config (--config) > DEFAULT_CONFIG

Override examples

Python API

from amorphgen import MeltQuenchPipeline

pipe = MeltQuenchPipeline(
    input_file="POSCAR",
    work_dir="my_run",
    cfg_override={
        "model": "mace-mpa-0",
        "device": "cuda",
        "opt": {"fmax": 0.05, "cell_filter": "none"},
        "eq_high": {"T": 3000, "steps": 200000, "timestep": 0.5},
        "quench": {"rate": 100, "timestep": 0.5},
    },
)
atoms = pipe.run(stages=[1, 4, 5, 6, 7], resume=True)

YAML config

model: mace-mpa-0
device: cuda

opt:
  fmax: 0.05
  cell_filter: none

eq_high:
  ensemble: NVT
  T: 3000
  steps: 200000
  timestep: 0.5

quench:
  ensemble: NVT
  T_start: 3000
  T_end: 300
  T_step: -100
  rate: 100
  timestep: 0.5