Command Line Interface and Configuration

Command Line Interface and Configuration#

Overview#

jrystal is a quantum chemistry calculation package that can be executed via command line interface. The program uses a YAML configuration file to specify calculation parameters and settings.

Command Line Interface#

The command line interface accepts the following options:

  • -m, --mode: Specifies the calculation mode (energy or band). Default: energy

  • -c, --config: Specifies the path to the configuration file. Default: config.yaml

Example Usage#

For total energy minimization:

jrystal -m energy -c config.yaml

For band structure calculation:

jrystal -m band -c config.yaml

Configuration File Structure#

The configuration file must be in YAML format and contain the following sections:

Crystal Structure

  • crystal: Identifier for the crystal structure. The program searches for $CRYSTAL.xyz in the geometry directory

  • crystal_file_path_path: Explicit path to the crystal structure file (takes precedence over crystal if both are specified)

Exchange-Correlation Functional

  • xc: Exchange-correlation functional specification (e.g., lda_x for Local Density Approximation exchange)

Pseudopotential Configuration

  • use_pseudopotential: Enables or disables pseudopotential calculations (True/False)

  • pseudopotential_file_dir: Path to pseudopotential files directory (uses system default if unspecified)

Planewave Basis Settings

  • freq_mask_method: Grid masking methodology:

    • cubic: Employs cubic grid masking

    • spherical: Employs spherical grid masking with user-defined cutoff

  • cutoff_energy: Planewave kinetic energy cutoff in Hartree (required for spherical method)

  • grid_sizes: Fast Fourier Transform (FFT) grid dimensions

  • k_grid_sizes: Monkhorst-Pack k-point grid dimensions for Brillouin zone sampling

  • occupation: Electronic state occupation methodology: can be chosen from simplex-projector, gamma, uniform, or idempotent:

    • simplex-projector: Simplex projector method

    • gamma: Gamma-point sampling scheme

    • uniform: Uniform occupation distribution

    • idempotent: Idempotent method

  • smearing: Fermi-Dirac distribution temperature parameter in Hartree

  • empty_bands: Number of additional unoccupied bands to compute

  • spin_restricted: Enforces identical spatial orbitals for spin-up and spin-down electrons (True/False)

Ewald Summation Parameters

  • ewald_args: Ewald sum configuration:

    • ewald_eta: Separation parameter for real/reciprocal space partitioning

    • ewald_cutoff: Reciprocal space cutoff radius

Optimization Parameters

  • epoch: Maximum optimization iteration count

  • optimizer: Optimization algorithm selection (e.g., adam)

  • optimizer_args: Algorithm-specific parameters:

    • learning_rate: Optimization step size

  • scheduler: Learning rate scheduling specification (null for constant rate)

  • convergence_condition: Energy variance threshold for convergence determination

Band Structure Calculation Parameters

  • band_structure_empty_bands: Number of unoccupied bands for band structure analysis

  • k_path_special_points: High-symmetry k-point sequence (e.g., LGXL)

  • num_kpoints: Sampling point count per k-path segment

  • k_path_file: Path to NumPy (.npy) file containing custom k-point coordinates

  • band_structure_epoch: Maximum band structure optimization iterations

  • k_path_fine_tuning: Enables progressive k-path optimization using previous solutions

  • k_path_fine_tuning_epoch: Iteration count per k-point during fine-tuning

System Configuration

  • seed: Random number generator seed for reproducibility

  • xla_preallocate: Enables XLA memory preallocation for performance optimization

  • jax_enable_x64: Activates double-precision (64-bit) floating-point computation

  • verbose: Controls computation progress output detail

  • eps: Numerical stability threshold for division operations

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