# Welcome to berry suite homepage

**berry** extracts the Bloch wavefunctions from DFT calculations in an ordered way so they can be directly used to make calculations.

In practice it retrieves the wavefunctions and their gradients in reciprocal space totally ordered by unentangled bands, where continuity applies.

In particular, it calculates the Berry connections and curvatures from DFT calculations.

The Berry connections can be used to calculate the first order optical conductivity and the second order optical conductivity for second harmonic generation (SHG).

This version 0.3.2 is a nice step forward in the development of the code, but it still has many things to improve. So far it can only be used with 2D materials and with DFT suite Quantum Espresso, on spinless calculations.

It is expected that this software will evolve with more possibilities in the near future.

### We wellcome contributors

The list of TODOs is huge at this stage, and people willing to contribute are very wellcome.

### Support or Contact

This project is maintained by Ricardo Mendes Ribeiro (ricardo.ribeiro@physics.org).