User Manual
Here, parameters employed in input.in are described.
[Active learning types]
1) calc_type (str): active (default), random
- Type of the data-sampling. active initiates an active learning scheme. random triggers a random sampling.
2) al_type (str): energy, force, force_max (default)
- Source of the uncertainty. Ensemble uncertainty is obtained from potential energy (energy) and averaged atomic forces (force). force_max means the maximum of the force uncertainty among different atoms.
3) uncert_type (str): absolute (default), relative
- Type of the uncertainty. absolute and relative mean the absolute and relative values of uncertainties, respectively.
4) uncert_shift (float): 2.0 (default)
- A shift of erf function at the middle point for the uncertainty sampling probability function. 1.0 corresponds to a standard deviation of the target uncertainty.
5) uncer_grad (float): 1.0 (default)
- A gradient of erf function at the middle point for the uncertainty sampling probability function, determining the softness of sampling criteria.
6) output_format (str): trajectory.son (default), aims.out
- Type of FHI-vibes output to be read.
7) MLIP (str): nequip (default), so3krates
[Active learning parameters]
1) nstep (int): 1 (default)
- The number of subsampling sets.
2) nmodel (int): 1 (default)
- The number of ensemble model sets with different random initializations.
3) ntrain_init (int): 25 (default)
- The number of training data for the initial MLIP models.
4) ntrain (int): 25 (default)
- The number of training data added for each iterative step.
5) nperiod (int): 200 (default)
- The number of MLIP-MD steps for the exploration during the active learning scheme.
[Molecular dynamics setting]
1) ensemble (str): NVTLangevin
- The type of molecular dynamics (MD) ensembles.
2) temperature (float): 300 (default)
- The desired temperature in units of Kelvin (K).
3) timestep (float): 1 (default)
- MD timestep in units of femto-second (fs).
4) loginterval (int): 1 (default)
- The step interval for printing and saving MD steps.
5) friction (float): 0.03 (default)
- The strength of the friction parameter in NVTLangevin ensemble.
[NequIP setting]
Only four parameters are assigned by the ALmoMD. The other setting is included in nequip.yaml.
1) rmax (float): 3.5 (default)
- The cutoff radius in the NequIP.
2) lmax (int): 2 (default)
- The maximum angular mommentum in the NequIP.
3) nfeatures (int): 16 (default)
- The number of features used in the NequIP.
4) E_gs (float): 0.0 (default)
- The reference total energy in units of eV/unitcell to shift the total energies. Recommend to use the total energy of the ground state structure.
[So3krates setting]
All parameters are employed. For examples,
- r_cut = 5.0
- loss_variance_scaling = ‘–loss-variance-scaling’
Please check the details in the So3krates website. Additionally, the refence energy, E_gs, needs to be assigned.
1) E_gs (float): 0.0 (default)
- The reference total energy in units of eV/unitcell to shift the total energies. Recommend to use the total energy of the ground state structure.
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