# asr.c2db.stiffness¶

## Summary¶

This is the documentation for `asr.c2db.stiffness`-recipe. This recipe is comprised of a single instruction, namely:

Run this recipe through the CLI interface

```\$ asr run asr.c2db.stiffness
```

or as a python module

```\$ python -m asr.c2db.stiffness
```

## Detailed description¶

Stiffness tensor.

## Steps¶

### asr.c2db.stiffness¶

asr.c2db.stiffness.main(atoms, calculator={'charge': 0, 'convergence': {'forces': 0.0001}, 'kpts': {'density': 6.0, 'gamma': True}, 'mode': {'ecut': 800, 'name': 'pw'}, 'name': 'gpaw', 'occupations': {'name': 'fermi-dirac', 'width': 0.05}, 'symmetry': {'symmorphic': False}, 'txt': 'relax.txt', 'xc': 'PBE'}, strain_percent=1.0, d3=False, fmax=0.01, enforce_symmetry=True)[source]

Calculate stiffness tensor.

Parameters
• atoms (ase.atoms.Atoms) –

• calculator (dict) –

• strain_percent (float) –

• d3 (bool) –

• fmax (float) –

• enforce_symmetry (bool) –

Return type

asr.c2db.stiffness.Result

class asr.c2db.stiffness.Result(c_51, c_11, c_63, c_32, c_64, c_62, c_31, c_53, c_56, c_26, eigenvalues, c_21, c_14, c_66, c_22, c_15, c_24, stiffness_tensor, c_33, c_41, c_43, c_65, dynamic_stability_stiffness, c_44, c_61, c_54, c_16, c_42, c_35, c_46, c_23, c_52, c_55, speed_of_sound_x, c_13, c_45, c_36, c_34, c_12, speed_of_sound_y, c_25)[source]
Parameters
property c_11: float

Stiffness tensor 11-component.

property c_12: float

Stiffness tensor 12-component.

property c_13: float

Stiffness tensor 13-component.

property c_14: float

Stiffness tensor 14-component.

property c_15: float

Stiffness tensor 15-component.

property c_16: float

Stiffness tensor 16-component.

property c_21: float

Stiffness tensor 21-component.

property c_22: float

Stiffness tensor 22-component.

property c_23: float

Stiffness tensor 23-component.

property c_24: float

Stiffness tensor 24-component.

property c_25: float

Stiffness tensor 25-component.

property c_26: float

Stiffness tensor 26-component.

property c_31: float

Stiffness tensor 31-component.

property c_32: float

Stiffness tensor 32-component.

property c_33: float

Stiffness tensor 33-component.

property c_34: float

Stiffness tensor 34-component.

property c_35: float

Stiffness tensor 35-component.

property c_36: float

Stiffness tensor 36-component.

property c_41: float

Stiffness tensor 41-component.

property c_42: float

Stiffness tensor 42-component.

property c_43: float

Stiffness tensor 43-component.

property c_44: float

Stiffness tensor 44-component.

property c_45: float

Stiffness tensor 45-component.

property c_46: float

Stiffness tensor 46-component.

property c_51: float

Stiffness tensor 51-component.

property c_52: float

Stiffness tensor 52-component.

property c_53: float

Stiffness tensor 53-component.

property c_54: float

Stiffness tensor 54-component.

property c_55: float

Stiffness tensor 55-component.

property c_56: float

Stiffness tensor 56-component.

property c_61: float

Stiffness tensor 61-component.

property c_62: float

Stiffness tensor 62-component.

property c_63: float

Stiffness tensor 63-component.

property c_64: float

Stiffness tensor 64-component.

property c_65: float

Stiffness tensor 65-component.

property c_66: float

Stiffness tensor 66-component.

property dynamic_stability_stiffness: str

Stiffness dynamic stability (low/high)

property eigenvalues: List[complex]

Stiffness tensor eigenvalues.

property speed_of_sound_x: float

Speed of sound (x) [m/s]

property speed_of_sound_y: float

Speed of sound (y) [m/s]

property stiffness_tensor: List[List[float]]

Stiffness tensor [N/m^{dim-1}]