AiiDA plugin for working with CASTEP

(master)
(dev)

This is a plugin for using CASTEP in AiiDA. The plugin is OK for production use, but improvment will be made from time to time. CASTEP has a single binary executable and calculation is primarily controlled by the task keyword. The generic CastepCalculation should work with all tasks, at least in terms of generating input files. Likewise a generic CastepParser class is implemented and can handle parsing most information we are interested in singlepoint, geometryoptimisation, bandstructure/spectral tasks. Things such as parsing output from phonon calculation has not been implemented so far - I have very little experience with phonon calculations. However, most output files are retrieved if present. If there is any missing it is possible to explicitly request retrieval from the remote computer. The raw files can always be analysed by the post-processing tools of your choice.

Highlights of available features:

• Storing usp/recpot as UspData (sub-class of SingleFileData) in AiiDA database and create/use of pseudo family groups.
• Store OTFG generating strings as OTFGData in AiiDA. Create of family/group are also supported. OTFG library (such as "C19") are represented as a OTFG string works for all elements.
• Preparation of CASTEP input files. Writing cell and parameters files are both supported. Tags in positions_abs block file should also work, e.g LABEL, SPIN, MIXTURE.
• Parsing energy, force, stress from output .castep file and .geom file
• Parsing trajectory from .geom, .ts, .md files.
• Checking errors in .param and .cell files before submitting
• Extra KpointData input node for BS, SEPCTRAL and PHONON tasks.
• Preparing transition state search calculations
• A create_restart method for easy creation of continuation/restart calculations. Input can be altered using param_update and param_delete keyword arguments. Automatic copying/linking of remote check files by AiiDA.
• A get_castep_inputs_summary method to print a summary of inputs of a calculations.
• A compare_with method to compare the inputs of two calculations.

Documentation

Documentation is hosted at Read the Docs:
dev version
master version

TODOS

• Methods for importing existing calculations
• Support for submitting file based CASTEP calculations.
• At the moment there is no enforcement on the type in Dict input node. For example, setting smearing_width to 0.1 and "0.1" is equivalent, but they will store differently in the database.
• WorkChain developments for automated relaxation and bandstructure calculations.

How to test

The tests uses the pytest framework. First, install with the dependencies

pip install aiida_core[testing]
pip install aiida-castep[testing]

Then you can run the command pytest from the project directory.