Py4vasp

*py4vasp* is a Python interface to extract data from VASP calculations. It is intended mainly to get a quick look at the data and provide the functionality to export it into common formats that can be used by other more sophisticated postprocessing tools. The second domain of application is for people that want to write Python scripts based on the data calculated by VASP. This tool interfaces directly with the new HDF5 file format and thereby avoids parsing issues associated with the XML or OUTCAR files.

For these two groups of users, we provide a different level of access. The simple routines used in the tutorials will read the data from the file directly and then generate the requested plot. For script developers, we provide interfaces to convert the data to Python dictionaries for further processing. If I/O access limits the performance, you can lazily load the data only when needed.

In addition, py4vasp provides utility scripts to assist with common workflows in VASP:

* *error-analysis* - This script extracts the energies, forces, and stress tensors of a machine-learned force-field calculation and compares them against a reference set of first principles calculations. The errors are returned as data or plot to assess the accuracy of the force field.

Changes
* feat: allow addition and subtraction in selection strings by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/93
* fix: creating Structure.from_POSCAR by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/95
* feat: Implement minimal py4vasp-core package by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/96
* feat: orbital moments by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/97
* fix: limit access to schema by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/100
* doc: add docstring to internal_strain.to_dict by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/101
* feat: access bandgap of VASP by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/98
* feat: add to_csv and to_frame by sudarshanv01 in https://github.com/vasp-dev/py4vasp/pull/103
* feat: provide additional functionality to deal with structures in py4vasp by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/106
* feat: create direct interface to force-field error analysis by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/108
* fix: make cell and structure backwards compatible by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/111
* feat: implement reading of the potential by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/110
* fix: schema for potential by sudarshanv01 in https://github.com/vasp-dev/py4vasp/pull/116
* fix: plotting of density by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/119
* fix: plotting of potential by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/123
* feat: plotting ncl densities by mt-huebsch in https://github.com/vasp-dev/py4vasp/pull/120
* doc: fix typo by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/140
* feat: Add OSZICAR information to HDF5 by sudarshanv01 in https://github.com/vasp-dev/py4vasp/pull/136
* feat: clearer separation of View logic some refinement code by martin-schlipf in https://github.com/vasp-dev/py4vasp/pull/142

New Contributors
* sudarshanv01 made their first contribution in https://github.com/vasp-dev/py4vasp/pull/103
* mt-huebsch made their first contribution in https://github.com/vasp-dev/py4vasp/pull/120

**Full Changelog**: https://github.com/vasp-dev/py4vasp/compare/v0.7.4...v0.9.0

This is a release of the code at the time of the *Moving ions for the advanced user* workshop

py4vasp is a python interface to extract data from VASP calculations. It is intended mainly to get a quick look at the data and provide the functionality to export it into common formats that can be used by other more sophisticated postprocessing tools. The second domain of application is for people that want to write python scripts based on the data calculated by VASP. This tool interfaces directly with the new HDF5 file format and thereby avoids parsing issues associated with the XML or OUTCAR files.

For these two groups of users, we provide a different level of access. The simple routines used in the tutorials will read the data from the file directly and then generate the requested plot. For script developers, we provide an expert interface where the data is lazily loaded as needed with some greater flexibility when the data file is opened and closed.

In addition, py4vasp provides utility scripts to assist with common workflows in VASP:
* _error-analysis_ - This script extracts the energies, forces, and stress tensors of a machine-learned force-field calculation and compares them against a reference set of first principles calculations. The errors are returned as data or plot to assess the accuracy of the force field.


Changes

* New features: pair correlation function, phonon band structure, phonon dos, ion velocities, BSE fatbands, more dielectric functions
* Improve package structure making clearer which modules are private/public.
* Rewrite the low level interface to make it more flexible and allow to collect data from multiple files.
* Fix Topology if the POTCAR contains the same element more than once.
* Refactor common functionality into Mixin classes.

Fixes with respect to py4vasp.0.7
* Make py4vasp compatible with Python 3.11
* Newer version of ipywidgets clash with the nglview package. We tie this dependency to the most recent version that still works until this is fixed in nglview.
* Set upper limit for IPython version to keep compatibility with python=3.8
* Fix a installation conflict with notebook>=7

py4vasp.0.7.3

py4vasp is a python interface to extract data from VASP calculations. It is intended mainly to get a quick look at the data and provide the functionality to export it into common formats that can be used by other more sophisticated postprocessing tools. The second domain of application is for people that want to write python scripts based on the data calculated by VASP. This tool interfaces directly with the new HDF5 file format and thereby avoids parsing issues associated with the XML or OUTCAR files.

For these two groups of users, we provide a different level of access. The simple routines used in the tutorials will read the data from the file directly and then generate the requested plot. For script developers, we provide an expert interface where the data is lazily loaded as needed with some greater flexibility when the data file is opened and closed.

In addition, py4vasp provides utility scripts to assist with common workflows in VASP:
* _error-analysis_ - This script extracts the energies, forces, and stress tensors of a machine-learned force-field calculation and compares them against a reference set of first principles calculations. The errors are returned as data or plot to assess the accuracy of the force field.


Changes

* New features: pair correlation function, phonon band structure, phonon dos, ion velocities, BSE fatbands, more dielectric functions
* Improve package structure making clearer which modules are private/public.
* Rewrite the low level interface to make it more flexible and allow to collect data from multiple files.
* Fix Topology if the POTCAR contains the same element more than once.
* Refactor common functionality into Mixin classes.

Fixes with respect to py4vasp.0.7
* Make py4vasp compatible with Python 3.11
* Newer version of ipywidgets clash with the nglview package. We tie this dependency to the most recent version that still works until this is fixed in nglview.
* Set upper limit for IPython version to keep compatibility with python=3.8

py4vasp.0.7.2

py4vasp is a python interface to extract data from VASP calculations. It is intended mainly to get a quick look at the data and provide the functionality to export it into common formats that can be used by other more sophisticated postprocessing tools. The second domain of application is for people that want to write python scripts based on the data calculated by VASP. This tool interfaces directly with the new HDF5 file format and thereby avoids parsing issues associated with the XML or OUTCAR files.

For these two groups of users, we provide a different level of access. The simple routines used in the tutorials will read the data from the file directly and then generate the requested plot. For script developers, we provide an expert interface where the data is lazily loaded as needed with some greater flexibility when the data file is opened and closed.

In addition, py4vasp provides utility scripts to assist with common workflows in VASP:
* _error-analysis_ - This script extracts the energies, forces, and stress tensors of a machine-learned force-field calculation and compares them against a reference set of first principles calculations. The errors are returned as data or plot to assess the accuracy of the force field.


Changes

* New features: pair correlation function, phonon band structure, phonon dos, ion velocities, BSE fatbands, more dielectric functions
* Improve package structure making clearer which modules are private/public.
* Rewrite the low level interface to make it more flexible and allow to collect data from multiple files.
* Fix Topology if the POTCAR contains the same element more than once.
* Refactor common functionality into Mixin classes.

Fixes with respect to py4vasp.0.7
* Make py4vasp compatible with Python 3.11
* Newer version of ipywidgets clash with the nglview package. We tie this dependency to the most recent version that still works until this is fixed in nglview.

py4vasp.0.7.1

Patch the [previous release](https://github.com/vasp-dev/py4vasp/releases/tag/v0.7) for Python 3.11.