References and Contributors
***************************

The path that leads to the current implementation of ChASE using modern
``C++`` design concepts started back in summer of 2012, when an
initial Matlab prototype of the code was implemented in ``C`` and
parallelized using OpenMP 3.0. Soon after a distributed version of the
code was implemented based on MPI and the `Elemental
<http://libelemental.org/>`__ library. The results of these
implementations lead to a the first publications on the performance of
the library on sequences of eigenvalue problems stemming from
Materials Science applications. In the following three years, a first
basic ``C++`` implementation on shared memory architectures and GPUs
was developed. Eventually all these efforts lead to the current
implementation in ``C++`` which is templated and separates algorithm
from kernel implementation through the use of an abstract class.

Main developers
================

  * Edoardo Di Napoli -- Algorithm design and development

  * Xinzhe Wu -- Algorithm development, advanced parallel (MPI and GPU) implementation and optimization, developer documentation

Current Contributors
=====================

  * Davor Davidović -- Advanced parallel GPU implementation and optimization

  * Nenad Mijić -- ARM-based implementation and optimization 
  
Past Contributors
===================

  * Xiao Zhang -- Integration of ChASE into Jena BSE code

  * Miriam Hinzen, Daniel Wortmann -- Integration of ChASE into FLEUR code

  * Sebastian Achilles -- Library benchmarking on parallel platforms, documentation

  * Jan Winkelmann -- DoS algorithm development and advanced ``C++`` implementation

  * Paul Springer -- Advanced GPU implementation

  * Marija Kranjcevic -- OpenMP ``C++`` implementation

  * Josip Zubrinic -- Early GPU algorithm development and implementation

  * Jens Rene Suckert -- Lanczos algorithm and GPU implementation

  * Mario Berljafa -- Early ``C`` and ``MPI`` implementation using the Elemental library

How to Reference the Code
==========================
The main reference of ChASE is [1] while [2] provides some early
results on scalability and usage on sequences of eigenproblems
generated by Materials Science applications.

  * [1] J. Winkelmann, P. Springer, and E. Di Napoli. *ChASE: a
    Chebyshev Accelerated Subspace iteration Eigensolver for sequences
    of Hermitian eigenvalue problems.* ACM Transaction on Mathematical
    Software, **45** Num.2, Art.21, (2019). `DOI:10.1145/3313828
    <https://doi.org/10.1145/3313828>`__ , [`arXiv:1805.10121
    <https://arxiv.org/abs/1805.10121/>`__ ]

  * [2] M. Berljafa, D. Wortmann, and E. Di Napoli. *An Optimized and
    Scalable Eigensolver for Sequences of Eigenvalue Problems.*
    Concurrency & Computation: Practice and Experience **27** (2015),
    pp. 905-922. `DOI:10.1002/cpe.3394
    <https://onlinelibrary.wiley.com/doi/pdf/10.1002/cpe.3394>`__ , [`arXiv:1404.4161
    <https://arxiv.org/abs/1404.4161>`__ ].

  * [3] X. Wu, D. Davidović, S. Achilles,E. Di Napoli. *ChASE: a distributed hybrid 
    CPU-GPU eigensolver for large-scale hermitian eigenvalue problems.* Proceedings 
    of the Platform for Advanced Scientific Computing Conference (PASC22). 
    `DOI:10.1145/3539781.3539792 <https://doi.org/10.1145/3539781.3539792>`__ , [`arXiv:2205.02491
    <https://arxiv.org/pdf/2205.02491/>`__ ]