abinit/tests/built-in

This directory contains the file needed for the build-in tests of the
abinit code (sequential version).

Please, see the README file in the tests directory (above this one) to get help.
_____________________________________________________________________

A set of seven build-in tests exist in the abinit code.
These short tests should be used as frequently as possible
in the course of development or modification of the existing code.

1) Usage

In the main directory, type the command `make` with one of the following keywords:

    - test_fast
    - test_v1
    - test_v5
    - test_libxc
    - test_bigdft
    - test_wannier90 

like: 

    $ make test_fast

The code (sequential version) will run automatically, and print on screen 
different status files during the execution, followed by an automatic check 
of the exactness of the results obtained (total energy, eigenvalues, 
nuclei positions,  forces and stresses). If everything is OK, the final output 
on screen is rather short:

--------------------------------------------
 Status file, reporting on built-in test fast

 ==> The run finished cleanly.
     Moreover, comparison of the total energy, and other (few) relevant quantities with reference values has been successful.
     This does not mean that no problem is present, however.
     Please run the complete set of ABINIT tests to gain a better confidence in your installation.

If there is a problem, the final output on screen will describe briefly
the error. 
--------------------------------------------

The computed values are converged up to some level of convergence.
The code takes into account predefined levels of convergence,
in such a way that this suite of test should still be valid if
the algorithm in the code is modified, even profoundly.
Indeed, only the final result is checked, not the intermediate results.
Unlike the basic algorithm, the parameters of the calculation  (ecut, ngfft, nkpt ...) 
should not change for this suite of test to be valid.

2) Description of the tests

test_fast:          H2 molecule, determination of the H-H distance by the Broyden algorithm. 
test_v1:            Yb cristal, self-consistent
test_v5:            HBe molecule, spin-polarized, determination of forces
test_bigdft:        H atom within BigDFT
test_libxc:         Bi atom with PAW, GGA PBE from LibXC
test_wannier90:     GaAs crystal with few bands.


The physical content is weak, because the cut-off energies are unreasonably low.


3) Related information

The files that define the suite of tests are contained in the built-in directory. 
These should NOT be changed, even for debugging. It is much better to do the debugging 
in the fast directory, or to duplicate the built-in directory, and not to rely on the 
"make" mechanism for the debugging.