frechet_cell_fire

torch_sim.optimizers.frechet_cell_fire(model, *, dt_max=1.0, dt_start=0.1, n_min=5, f_inc=1.1, f_dec=0.5, alpha_start=0.1, f_alpha=0.99, cell_factor=None, hydrostatic_strain=False, constant_volume=False, scalar_pressure=0.0, max_step=0.2, md_flavor=ase_fire_key)[source]

Initialize a batched FIRE optimization with Frechet cell parameterization.

Creates an optimizer that performs FIRE optimization on both atomic positions and unit cell parameters using matrix logarithm parameterization for cell degrees of freedom. This parameterization provides forces consistent with numerical derivatives of the potential energy with respect to cell variables, resulting in more robust cell optimization.

Parameters:

  • model (Module) – Model that computes energies, forces, and stress.

  • dt_max (float) – Maximum allowed timestep

  • dt_start (float) – Initial timestep

  • n_min (int) – Minimum steps before timestep increase

  • f_inc (float) – Factor for timestep increase when power is positive

  • f_dec (float) – Factor for timestep decrease when power is negative

  • alpha_start (float) – Initial velocity mixing parameter

  • f_alpha (float) – Factor for mixing parameter decrease

  • cell_factor (float | None) – Scaling factor for cell optimization. If None, defaults to number of atoms per batch

  • hydrostatic_strain (bool) – Whether to only allow hydrostatic deformation (isotropic scaling)

  • constant_volume (bool) – Whether to maintain constant volume during optimization

  • scalar_pressure (float) – Applied external pressure in GPa

  • max_step (float) – Maximum allowed step size for ase_fire

  • md_flavor ("vv_fire" | "ase_fire") – Optimization flavor. Default is “ase_fire”.

Returns:

A pair of functions:

  • Initialization function that creates a FrechetCellFIREState

  • Update function that performs one FIRE step with Frechet derivatives

Return type:

tuple

Notes