# asr.berry¶

## Summary¶

This is the documentation for `asr.berry`-recipe. This recipe is comprised of 2 instructions, namely:

Run this recipe through the CLI interface

```\$ asr run asr.berry
```

or as a python module

```\$ python -m asr.berry
```

## Detailed description¶

Topological analysis of electronic structure.

## Steps¶

### asr.berry:calculate¶

asr.berry.calculate(atoms, calculator={'charge': 0, 'convergence': {'bands': 'CBM+3.0'}, 'kpts': {'density': 12.0, 'gamma': True}, 'mode': {'ecut': 800, 'name': 'pw'}, 'name': 'gpaw', 'nbands': '200%', 'occupations': {'name': 'fermi-dirac', 'width': 0.05}, 'txt': 'gs.txt', 'xc': 'PBE'}, kpar=120, kperp=7)[source]

Calculate ground state on specified k-point grid.

Parameters
Return type

`asr.berry.CalculateResult`

class asr.berry.CalculateResult(s0_pi_km, phi2_km, phi0_pi_km, phi1_km, phi0_km, s1_km, s2_km, s0_km)[source]
Parameters
• s0_pi_km (numpy.ndarray) –

• phi2_km (numpy.ndarray) –

• phi0_pi_km (numpy.ndarray) –

• phi1_km (numpy.ndarray) –

• phi0_km (numpy.ndarray) –

• s1_km (numpy.ndarray) –

• s2_km (numpy.ndarray) –

• s0_km (numpy.ndarray) –

property phi0_km: numpy.ndarray

Berry phase spectrum at k_2=0, localized along the k_0 direction

Return type

`numpy.ndarray`

property phi0_pi_km: numpy.ndarray

Berry phase spectrum at k_2=pi, localized along the k_0 direction

Return type

`numpy.ndarray`

property phi1_km: numpy.ndarray

Berry phase spectrum at k_0=0, localized along the k_1 direction

Return type

`numpy.ndarray`

property phi2_km: numpy.ndarray

Berry phase spectrum at k_1=0, localized along the k_2 direction

Return type

`numpy.ndarray`

property s0_km: numpy.ndarray

Expectation value of spin in the easy-axis direction for the Berry phases at k_2=0

Return type

`numpy.ndarray`

property s0_pi_km: numpy.ndarray

Expectation value of spin in the easy-axis direction for the Berry phases at k_2=pi

Return type

`numpy.ndarray`

property s1_km: numpy.ndarray

Expectation value of spin in the easy-axis direction for the Berry phases at k_0=0

Return type

`numpy.ndarray`

property s2_km: numpy.ndarray

Expectation value of spin in the easy-axis direction for the Berry phases at k_1=0

Return type

`numpy.ndarray`

### asr.berry¶

asr.berry.main(atoms, calculator={'charge': 0, 'convergence': {'bands': 'CBM+3.0'}, 'kpts': {'density': 12.0, 'gamma': True}, 'mode': {'ecut': 800, 'name': 'pw'}, 'name': 'gpaw', 'nbands': '200%', 'occupations': {'name': 'fermi-dirac', 'width': 0.05}, 'txt': 'gs.txt', 'xc': 'PBE'}, kpar=120, kperp=7, topology='Not checked!')[source]
Parameters
Return type

`asr.berry.Result`

class asr.berry.Result(Topology)[source]
Parameters

Topology (str) –

property Topology: str

Band topology.

Return type

`str`