Lobsterpy

0.6.0 · active · verified Fri Apr 17

Lobsterpy is a Python package designed for automatic bonding analysis derived from LOBSTER calculations, which themselves process VASP output. It helps researchers analyze chemical bonding in materials efficiently. The current version is 0.6.0, and the project is under active development with irregular but consistent releases.

Common errors

```
ModuleNotFoundError: No module named 'lobsterpy.analysis'
```
cause The `analysis` submodule was moved or renamed in recent versions.

fix Change your import statement from `from lobsterpy.analysis import LobsterpyAnalysis` to `from lobsterpy.cohp.analyze import LobsterpyAnalysis`.
```
FileNotFoundError: [Errno 2] No such file or directory: 'path/to/your/lobster/calculation/COHPCAR.lobster'
```
cause The specified calculation directory either does not exist, or essential LOBSTER/VASP output files are missing within it.

fix Ensure the `path_to_lobster_calc` variable points to a valid directory containing all expected LOBSTER and VASP output files. Check for typos in the path and file names.
```
TypeError: __init__ got an unexpected keyword argument 'path'
```
cause The `LobsterpyAnalysis` constructor parameter for the calculation path changed from `path` to `path_to_lobster_calc` in version 0.5.0.

fix Update your constructor call from `LobsterpyAnalysis(path=...)` to `LobsterpyAnalysis(path_to_lobster_calc=...)`.

Warnings

breaking Major refactoring in versions >=0.5.0 moved key classes and changed method signatures. `LobsterpyAnalysis` and `LobsterpyData` are now in `lobsterpy.cohp.analyze` and `lobsterpy.cohp.data` respectively.
Fix: Update your imports from `from lobsterpy.analysis import ...` to `from lobsterpy.cohp.analyze import ...` and `from lobsterpy.data import ...` to `from lobsterpy.cohp.data import ...`. Review the changelog for specific method signature changes.
gotcha The `LobsterpyAnalysis` constructor requires a complete LOBSTER/VASP calculation directory. Missing essential files (e.g., `COHPCAR.lobster`, `vasprun.xml`, `POSCAR`) will lead to `FileNotFoundError` or parsing errors.
Fix: Verify that `path_to_lobster_calc` is a valid path and contains all required output files from a successful LOBSTER calculation (e.g., COHPCAR.lobster, ICOHPCAR.lobster, DOSCAR.lobster, vasprun.xml, POSCAR, KPOINTS, POTCAR, INCAR).
deprecated Direct plotting functions within `LobsterpyAnalysis` have been largely deprecated or moved. For plotting, use the dedicated `lobsterpy.plotting` module introduced in version 0.6.0.
Fix: Instead of calling methods like `analyzer.plot_cohps()`, import plotting functions from `from lobsterpy.plotting import plotting` (or similar) and pass the analysis data to them.

Install

pip install lobsterpy Install stable version

Imports

LobsterpyAnalysis
wrong:
```
from lobsterpy.analysis import LobsterpyAnalysis
```
correct:
```
from lobsterpy.cohp.analyze import LobsterpyAnalysis
```
The main analysis class was moved to the `cohp.analyze` submodule in recent versions (>=0.5.0).
LobsterpyData
wrong:
```
from lobsterpy.data import LobsterpyData
```
correct:
```
from lobsterpy.cohp.data import LobsterpyData
```
The data container class was moved to the `cohp.data` submodule in recent versions (>=0.5.0).

Quickstart

This example demonstrates how to initialize `LobsterpyAnalysis` with a LOBSTER/VASP calculation directory and extract basic bonding and population data. Ensure the `path_to_lobster_calc` variable points to a directory containing all necessary LOBSTER and VASP output files.

from pathlib import Path
from lobsterpy.cohp.analyze import LobsterpyAnalysis

# NOTE: Replace with the actual path to your LOBSTER/VASP calculation directory.
# This directory should contain files like COHPCAR.lobster, vasprun.xml, POSCAR etc.
# For a runnable example, you would need to set up such a directory locally.
path_to_lobster_calc = Path('/path/to/your/lobster_calculation_output')

# Create an instance of LobsterpyAnalysis
try:
    analyzer = LobsterpyAnalysis(
        path_to_lobster_calc=path_to_lobster_calc,
        gaussian_smearing_width=0.05,
        spin_type='none' # or 'up', 'down' for spin-polarized calculations
    )

    # Access bonding analysis results
    bond_data = analyzer.bond_analysis
    print("Bond Analysis:\n", bond_data)

    # You can also get population data
    population_data = analyzer.get_population_data()
    print("Population Data:\n", population_data)

except FileNotFoundError as e:
    print(f"Error: Calculation path not found or missing files. {e}")
    print("Please ensure 'path_to_lobster_calc' points to a valid LOBSTER/VASP calculation directory.")
except Exception as e:
    print(f"An error occurred during analysis: {e}")

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