Introduction

ESCDF are data representation standards based on HDF5 for large data sets (wave-functions, expansion coefficients, electron density, local density of states, etc.).

These standards are the result of a collaboration between the ESL, the NOMAD Center of Excellence, and the EUSpec Network.

Tools for the simpler reading and writing of these representations are coded in the library libescdf, which is under development.

Both the standards and the tools originate from a first standardisation effort done in the European Nanoquanta Network of Excellence, which resulted in the ETSF File Format Specifications.

Motivations

The main objectives of this data format are the following:

• enable a platform-independent exchange of data between electronic-structure programs;
• provide specifications which are both flexible and suitable for High-Performance Computing (HPC);
• hide the gory details of the I/O implementation, in particular the way parallelism is handled;
• facilitate, strengthen and extend interdisciplinary collaborations within and without the electronic-structure community.

Use cases

The current version of the format is intended to support the following use cases:

• restarting a calculation;
• exchanging data between 2 codes in a multi-step calculation;
• visualisation.