chemparseplot

How-to: Parse ORCA NEB Calculations#

Problem#

You have an ORCA NEB calculation and want to extract energies, geometries, and barriers.

Solution#

For ORCA 6.1+ (Recommended)#

Use OPI-based parser:

from pathlib import Path
from chemparseplot.parse.orca.neb import parse_orca_neb

data = parse_orca_neb("job", working_dir=Path("calculation"))

# Access parsed data
energies = data["energies"]  # eV
n_images = data["n_images"]
barrier = data["barrier_forward"]
converged = data["converged"]

For ORCA < 6.1#

Use legacy .interp file parser:

from pathlib import Path
from chemparseplot.parse.orca.neb import parse_orca_neb_fallback

data = parse_orca_neb_fallback("job", Path("calculation"))

if data is None:
    print("Parsing failed - check .interp file exists")

Automatic Fallback#

Let the parser choose automatically:

from chemparseplot.parse.orca.neb import parse_orca_neb, HAS_OPI

if HAS_OPI:
    data = parse_orca_neb("job", Path("calc"))
else:
    data = parse_orca_neb_fallback("job", Path("calc"))

Data Format#

Returned dictionary contains:

Key	Type	Description
`energies`	`np.ndarray`	Energies in eV
`rmsd_r`	`np.ndarray` or `None`	RMSD from reactant
`rmsd_p`	`np.ndarray` or `None`	RMSD from product
`grad_r`	`np.ndarray` or `None`	Gradients (RMSD-r)
`grad_p`	`np.ndarray` or `None`	Gradients (RMSD-p)
`forces`	`list` or `None`	Force vectors
`converged`	`bool`	Normal termination
`n_images`	`int`	Number of NEB images
`barrier_forward`	`float` or `None`	Forward barrier (eV)
`barrier_reverse`	`float` or `None`	Reverse barrier (eV)
`source`	`str`	`'opi'` or `'legacy_interp'`
`orca_version`	`str`	ORCA version string

See Also#