/********************************************************************

WELOCOME TO THE "ABACUS" PROGRAM.

(1) ABACUS stands for

"Atomic-orbital Based Ab-initio Computation at UStc"

See also the ABACUS webpage 

http://abacus.ustc.edu.cn

(2) There is a sub-package called

"SIA" stands for "Systematically Improvable Atomic orbitals generator"

COPYRIGHT 2018, the ABACUS team, Key Laboratory of Quantum Information,
University of Science and Technology


If you have any problems.
Contact: Lixin He
Email: helx@ustc.edu.cn

/********************************************************************



---------------------------------------------------------------------
There are generally 4 directories in this package.

bin:
Contains some executable files.

examples:
Contains test examples.

source:
Contains the source code and various makefiles for different hardware platforms.

tools:
Contains the script for generating numerical atomic orbitals.

---------------------------------------------------------------------
Currently ABACUS provides the following features and functionalities:

1. Ground-state total energy calculations using Kohn-Sham (KS) density functional theory
(DFT) with local-density or generalized gradient approximations (LDA/GGAs).
2. Brillouin zone sampling using the Monkhorst-Pack special k-points.
3. Geometry relaxation with both Conjugated Gradient (CG) and BroydenFletcherGoldfarbShanno (BFGS) methods.
4. Semi-empirical van der Waals energy correction using the Grimme DFT-D2/D3 scheme.
5. NVT molecular dynamics simulation using the Nose-Hoover thermostat. 
6. Stress calculation and cell relaxation.
7. Electric polarization calculation using Berry Phase theory.
8. Interface to the Wannier90 package.
9. Real-time time dependent density functional theory (TDDFT).
10. Electrostatic potential.
11. Mulliken charge analysis.
12. Projected density of states (PDOS).

---------------------------------------------------------------------
The developers of ABACUS include

Advisor:
*Lixin He 		2006~
 Xinguo Ren             2013~

Developers:

Now:
Mohan Chen      2006~ (Setting up the infrastructure of the codes)
Xiaohui Liu             2012~ (Overall structure, code optimization, charge extrapolation, MD, test)
Yu Shen                 2016~ (Interface to the ELPA library, performance optimization, efficient parallelization)
Weishuai Zhang          2016~ (Pseudoptential and numerical orbital basis generation)
Pengfei Li              2012~ (Orbital generation, CG, Symmetry, test)
Peize Lin               2013~ (vdwD2, hybrid functional)
Daye Zheng              2013~ (MD, stress tensor)
Fuxiang He              2015~ (TDDFT)
Gan  Jin                2016~ (Berry phase, interface to Wannier90)
Yuyang Ji               2019~ (vdwD3, hybrid functional)

Former:
Jie Liu 		2007~2008 (Makefile, Speed up using C++)
Ming Gong		2008~ (EPM, small box, spin-orbital coupling)
Shipeng Shu		2008~2009 (Symmetry2, MLWF)
Yuwei Cui		2008~2009 (Nearest neighbour searching, BFGS)
Pan Zheng		2007~2008 (Symmetry)
Chen Liao               2008~2011 (Two-center integration, Force, Ylm)
Jianping Wang           2008~2014 (DMM, sparse matrix)
Chaobin Yang            2010~2011 (Parallel Matrix Diagonalization)
Yi Xia                  2010~2011 (Polarization)
Kai Chen                2010~2011 (Sparse Matrix Operations)