<html>
<head>
<title>v6 : README</title>
</head>
<body>

<h5>Copyright (C) 2002-2012 ABINIT group (FJollet, MTorrent, GZerah, XGonze, DHamann, MVeithen)
<br> This file is distributed under the terms of the GNU General Public License, see
~abinit/COPYING or <a href="http://www.gnu.org/copyleft/gpl.txt">
http://www.gnu.org/copyleft/gpl.txt </a>.
<br> For the initials of contributors, see ~abinit/doc/developers/contributors.txt .
</h5>

<pre>

This directory, v6, contains tests which
are related to the development of the various development in
version 6.x.x of Abinit
This file gives first a very brief description
of the tests, then a much longer one.

A classification of the tests is provided now. Later, each test is described
in more detail, with accompanying notes and references (some of the notes
might have to be updated, due to the small possible drift related to improvement
of the accuracy of the code).

------------------------------------------------------------------

* Tests 1-20 concern ground state (excluding PAW, to be placed in 41-49)
  also tests 31-34

* Tests 21-30 are related to geometry optimization, molecular dynamics, etc

* Tests 41-49 are related to PAW (excluding response functions,
    and electronic excitations, both to be placed later).

* Tests 35-40 and 50-99 concern response functions

------------------------------------------------------------------
***************

To run these tests, do the following:

0. Be sure that the perl script "run-standard-tests", in the main directory,
   has been generated from the primitive file "run-standard-tests.pl",
   thanks to the command "make perl"
   issued in ~abinit (see the installation notes on the Web).

1. Submit the "run-standard-tests" script, specifying a machine, and
   the keyword "v6" (for Tests_v6) and either
   the index of a test case, i.e.
   (run-standard-tests name_of_machine v6 22) >& log_file
   or a whole range of test cases (two indices), i.e.
   (run-standard-tests name_of_machine v6 02 08) >& log_file
   or, if you want to run all the test cases of this directory
   (run-standard-tests name_of_machine v6) >& log_file
   This will send stdout and stderr to log_file.
   The script 'run-standard-tests', will create a subdirectory of ~abinit/tests/v6,
   with the name_of_machine and the
   date, where all the results will be placed.

2. In that directory, you will find for each test case that you have
   run, a log file (with the name of the test case), an output
   file, but also a 'diff.xxx' file, automatically created by making
   a 'diff' with respect to the "Refs" subdirectory output files.
   It contains output files from a recent version of the ABINIT code.
   There may be large differences in timing but there should only
   be minor differences in the output of physical quantities.

3. There is also a global report file, generated by the use of the
   fldiff script. Its name is fldiff.report . See the last
   version of the  ~abinit/doc/install_notes/install** file
   in the Infos directory for information about the use of this file.
   This file is the most convenient for a quick look at the correctness
   of results. When the results are not correct, one has often to
   rely on the 'diff.xxx' file to understand what was going wrong.


**********

Test cases:

 (Tests 1-20 concern ground state)

 01. Chain of Silicon diatomic molecules (4 Si2 molecules in the cell)
     Freeze oscillatory perturbations with different wavelengths and intensities,
     thanks to the qprtrb and vprtrb input variables.
     This should be linked with the computation of the dielectric constant,
     test v2#05, that uses directly the RF capabilities of ABINIT,
     for one diatomic molecule.

     For dataset 1, one reproduces the results obtained in Tv2#05, multiplied by 4.
     The total energy is consistent up to more than 10 digits :
     -6.6499924738006 Ha for Tv2#05, -26.599969895203 Ha for the present calculation.

     For dataset 2, the perturbation qprtrb 0 0 1 is frozen in, with vprtrb 100.
     The total energy is -26.600317638775 Ha. The difference wrt the unperturbed situation is
     0.000348743572 Ha.

     For dataset 3, a much smaller perturbation (10 times smaller) is taken,
     giving total energy -26.599973367786 Ha. The difference wrt the unperturbed situation is
     0.3472583 microHa.

     For dataset 4, an even smaller perturbation (100 times smaller) is taken,
     giving total energy -26.599969929928 Ha. The difference wrt the unperturbed situation is
     0.000034725 microHa. With datasets 3 and 4, we are in the linear regime.
     The previous amplitude is better for such studies.

     Dataset 5 is the same as 3, with reversed amplitude. Results are similar to dataset 3.

     I had no sufficient time to analyze these data correctly and make the connection with the
     results of Tv2#05, unfortunately. The following (also test 02 below) gives some more data, and raise questions.
     There might be some problem with the use of qprtrb and vprtrb.

     For dataset 2, the group of the four lowest eigenenergies (each corresponding to a different molecule) is :
     -0.47198  -0.46381  -0.46091  -0.45266 , whose spread is 0.01932 Ha.
     One might think that the maximum and minimum of the potential are separated roughly by 0.02 Ha.
     The value vprtrb 100 corresponds to a cosine wave whose amplitude is 100, divided by the volume
     of the cell, that is 5000 Bohr^3 : 0.02 Ha. The maximum
     and minimum of the potential should thus be separated by 0.04 Ha. There seems to be a factor of 2 off.

 02. Chain of Silicon diatomic molecules (4 Si2 molecules in the cell)
     Freeze oscillatory perturbations with different wavelengths and intensities,
     thanks to the qprtrb and vprtrb input variables.
     Compute the dielectric constant. Similar to test v6#01,
     but uses a more symmetric geometry, to examine invariance
     of the response with respect to shifts of potential, and also
     a shorter wavelength. I do not understand why vprtrb 0 10.0 leads to no response.
     Such a sine wave should cause similar response as for the cosine wave.
     No time presently to investigate this problem (XG090909)
     (contributed by X. Gonze)

 03. Chain of Silicon diatomic molecules (1 Si2 molecule in the cell)
     Uses different values of fftcache. Test similar to B3 of the cpu series (case with ecut=112 and ngfft=3*96).
     The default fftcache=16 seems OK :
     With fftcache=1, the tcpu/ncalls/ndata is 0.028 on testf (the reference machine, 20090912)
     With fftcache=16 (the default), the tcpu/ncalls/ndata is 0.021
     With fftcache=128, the tcpu/ncalls/ndata is 0.021

 04. Hydrogen dimer in a big cell.
     Produce different files (_DEN, _POT, _VHXC, _VHA), for subsequent analysis by CUT3D (see next run).
     Note the following values, that will allow to check the correctness of the subsequent analysis :
     Kinetic energy  =  1.02998395409183E+00
     Hartree energy  =  8.05073794254872E-01
     Loc. psp. energy= -2.53949740885919E+00
     Band energy (Ha)=  -7.2732761066E-01
     Also, the mean of the Vxc potential is announced to be
     Average Vxc (hartree)=  -0.05293

 05. Hydrogen dimer in a big cell.
     Read the previously generated files, and analyze them separately, as well as jointly.
     Remarkable values of the separate analysis :
     - the integral of the charge density over the volume of the unit cell is 2.0
     - the mean of the Hartree potential vanishes (G=0) component
     - the mean of the Kohn-Sham and XC potentials are the same (as their difference would come from non-zero G=0
          contributions from the local potential and Hartree potential), that is
       Sum of values, mean, mean times cell volume=   -6.859211E+03   -5.292601E-02   -7.938901E+01
     - the mean of the XC potential -5.292601E-02 is in perfect agreement with the one from the previous run.
     Remarkable values of the joint analysis :
     - the integral of the product of charge density and Hartree potential over the volume of the unit cell is
        1.610148E+00, correctly twice the Hartree energy.
     - the integral of the product of charge density and Kohn-Sham potential over the volume of the unit cell is
        -1.757312E+00, correctly, the difference between the band energy and kinetic energy.


 06. NaCl molecule in a big box.
     Test of the computation of the polarisation with the routine berryphase_new,
     for different k-point grids : only 1 k-point, a line of k-points, and a full mesh of k-points.
     Results with acell 20 10 10 are : -9.727 C/m^2, -9.975 C/m^2, -9.503 C/m^2
       multiplied by the volume (in a.u.), gives -19454, -19950, -19006
     Test provided by S. Leroux

     Going to bigger cells make these results converge to the same value :
     Results with acell 30 20 20 are : -1.771 C/m^2, -1.746 C/m^2, -1.747 C/m^2
       multiplied by the volume (in a.u.), gives -21252, -20952, -20964
     Results with acell 40 20 20 are : -1.3167C/m^2, -1.3057C/m^2, -1.3062C/m^2
       multiplied by the volume (in a.u.), gives -21067, -20891, -20899
     Results with acell 50 20 20 are : -1.0502C/m^2, -1.0444C/m^2, -1.0450C/m^2
       multiplied by the volume (in a.u.), gives -21004, -20888, -20900

 07. NiO with 4 atoms. Check of the modified self-consistent loop over electronic density for DMFT. This
     calculation use LDA occupations for the test and is not running the DMFT part (dmftcheck2=-1).

 08. Print out CIF file for titanium bulk crystal prtcif variable. Hexagonal close packed Ti unit cell
     From M. Verstraete

 09. Print out CIF file for simple cubic Ti crystal, for reference purposes (conventional = primitive unit cell for symmetry ops)
     From M. Verstraete

 10. Read in Silane positions and znucl from an .xyz format file t10.in.xyz
     Demonstrates the use of the xyzfile input variable (from M. Verstraete)

 11. Print out geometry and eigenvalue files for analysis by the BoltzTraP code, for transport coefficients,
     Seebeck, etc... Tests the prtbltztrp input variable (from M. Verstraete)

 12. Isolated Hydrogen atom.
     Treated with GGA C09x exchange functional (ixc=24).
     The total energy is -0.429523 Ha.
     Also additional tests concerning the kinetic energy density calculation,
     the gradient of electronic density calculation and
     the Laplacian of electronic density calculation are performed.
     Test taken from v1/t21.in.

 13. Isolated Helium atom.
     Treated with GGA C09x exchange functional (ixc=24).
     The total energy is -2.7881 Ha.
     Test taken from v1/t10.in.

 14. MgB2, space group P6/m m m (#191); Bravais hP (primitive hexag.)
     GS calculation followed by a band structure calculation in which the
     k-path is automatically defined via the ndivsm input variable.
     The third dataset tests the calculation and the output of the Fermi surface (prtfsurf=1)
     in the Xcrysden format. Test provided by Matteo Giantomassi

 15. Test the symmetry finder for all the Bravais lattices,
     with different input formats (rprim or angdeg), and for
     non-conventional choices of axes as well.
     Uses only one atom, placed at (0.6 0 0)
     Similar to test v2#52, except for the choice of the location

 16. Set of Hydrogen atoms in a body-centered, or face-centered tetragonal, of body-centered orthorhombic lattice.
     This is to test the scalecart input variable.

 17. Bi atom in a big supercell.
     Test the application of a Zeeman field.

 18. HI 8 molecule per cell, the cell is triclinic.
     Prepare the density for the next Bader analysis.

 19. HI 8 molecule per cell, the cell is triclinic.
     Bader analysis for the first atom.
     Previously, there was a bug, not active when the cell has symmetric axes.

 20. Test of berrystep
     Al-As cristal, zinc-blende structure
     Compute the polarization along strings
     of k-points parallel to the primitive vectors of the reciprocal
     lattice, and using multiple step berry phase calculation.

 (Tests 21-30 are related to geometry optimization, molecular dynamics, etc)

 21. Bismuth, rhombohedral, two atoms per unit cell
     Scalar relativistic.
     Relax four different images, using the steepest descent algorithm.

 22. Hydrogen diatomic molecule in a cell, close to BCC.
     One hydrogen atom is at the origin. The other lies initially
     along the 1 1 1 direction, at a distance close to the one of the free dimer distance.
     The final position is the mirror with respect to the plane perpendicular to x, passing at 1/2 0 0 .
     The cell parameter is less than twice the H2 interatomic distance, so that the transition
     path come close to the x axis, although it never reaches it (the closest being in the
     mirror plane).

     Test the images : 6 images, exploring the transition path by a simple algorithm.

 23. Delocalized internals test. Si diamond bulk with displaced atom
     Unconverged in all variables (contributed by MJ Verstraete)

 24. Hydrogen diatomic molecule in a cell, close to BCC
     Test the string method : 6 images, exploring the transition
     path. Similar to test 22 (but with string).

 25. Hydrogen diatomic molecule in a cell, close to BCC
     Test the string method : 6 images, exploring the transition
     path but keeping X coordinated fixed. Similar to test 24

 26. (TO BE MODIFIED BY GREGORY)
     Hydrogen diatomic molecule in a cell, close to BCC
     Test the string method : 6 images, exploring the transition
     path but keeping X coordinated fixed. Similar to test 24

 27. Genetic algorithm structure random search.
     Hydrogen has been used as an example. No physical meaning.
     Number of images is only 10 but experience shows that at
     least 20 are fine.

 28. Ga Al(1-x) Asx
     Test of alchemical calculations with images.
     Mostly checking the treatment of input variables and their echo.

 (Tests 30-36 are more slots for testing the ground state)

 30. Hydrure of Lithium-Boron, in a face-centered monoclinic cell.
     Test the recognition of the space group (C2/c (# 15)). Was lacking a case before Dec 2011.
     Contributed by D. Klug

 31. Tests series for the mGGA implementation (from 31 to 33)
     Silicon bulk. Two datasets are run. One (classic) LDA calculation with ixc 7.
     One with a fake native mGGA (fake1, i.e. ixc 31) and using effmass=1.01.
     Both calculation should give the same total energy (change in kinetic energy due to
     effmass is compensated by the fake mGGA using kinetic energy density: taur).
     (Two other datasets are also run for spin polarized case)

 32. Test the mGGA implementation. Silicon bulk. Two datasets are run.
     One with a fake native mGGA (fake2, i.e. ixc 32) involving laplacian of the density.
     One with a fake native mGGA (fake3, i.e. ixc 33) involving gradient of the density.
     Both calculation should give the same total and exchange-correlation energies.
     (Two other datasets are also run for spin polarized case)

 33. Test the mGGA implementation. Isolated Hydrogen atom. Two datasets are run.
     One with a fake native mGGA (fake3, i.e. ixc 33) involving gradient of the density.
     One with a fake native mGGA (fake4, i.e. ixc 34) involving kinetic energy density (and its gradient).
     Both calculation should give the same total and exchange-correlation energies.
     (Two other datasets are also run for spin polarized case)

 34. Crystalline silicon. Diamond structure.
     Quick test of the use of datasets with a numbering beyond 1000 (the last one is 1022).

 (Tests 35-40 are for response-function)

 35. Generate first-order responses for FCC Aluminum.
     Very low cut-off, to keep CPU the lowest possible
     Aim at a regular sampling of phonon wavevectors, needed to
     interpolate the dynamical matrix over the whole Brillouin Zone.
     Use the definition through qptrlatt.
     Otherwise, similar to Tv2#26 and Tv6#78.

 36. ZrO2 FCC (fluorite structure).
     Compute the phonon frequencies at the X point.
     This worked correctly before 5.2.4, but then, an erroneous bug fix (correcting v5#21) was introduced.
     Final (correct) fixing in v6.0.4.
     (Contributed by I. Lukacevic, trying to reproduce results by Detraux et al 1997)

 37. Diamond.
     Test temperature-dependent of the electronic structure, with
     reduction of the number of q points to be computed, thanks to thmflag=7 .
     Warning : only valid for Gamma, AND the temperature-dependent shifts must be averaged
     over degenerate states.

 38. Merge the DDB from test 37

 39. Merge the EIGR2D files from test 37

 40. Use anaddb to compute the T-dependent correction.

 (Tests 41-49 are related to PAW)

 41. Test ujdet. Compute U in cells containing 2, 16 and 128 atoms.
     (contributed by DJ Adams)

 42. PAW Berrys Phase calculation of Born effective charge in AlAs by
     finite differences (contributed by J. Zwanziger, adapted from efield
     tutorial).

 43. PAW Berrys Phase calculation of Born effective charge in AlAs by
     finite electric fields (contributed by J. Zwanziger, adapted from efield
     tutorial).

 44. Electric field gradient of indium metal, body-centered tetragonal, included to
     check EFG symmetry in this case.
     (contributed by J. Zwanziger)

 45. DMFT tests on ferromagnetic NiO (2 atoms), check DMFT for several
     values of dmft_solv : computes occupations and energy.
     (contributed by B. Amadon)

 46. DMFT tests on Antiferromagnetic NiO (4 atoms), check DMFT loop with Hubbard I, DMFT
     self-consistency and density self-consistency : computes occupations and energy.
     (contributed by B. Amadon)

 47. DMFT on Gd (f-orbitals) without spin-orbit coupling : compute occupations and energy.
     (contributed by B. Amadon)

 48. Orbital magnetization of silicon. (contributed by J. Zwanziger)

 49. Electric field gradients in ICl molecule, with and without spin orbit coupling (contributed by J. Zwanziger)

 (Tests 50-99 concern response functions)

 50. He BCC primitive cell. Fake smooth pseudopotential.
     For testing the electron-phonon modification of the electronic structure.
     To be compared with the results of tests 51 to 59.
     Use a 2x2x2 grid of k (shifted) and q (non-shifted) points.
     No imaginary frequences for the phonons with this choice.
     Computation of the electronic eigenvalues as well as phonon eigenfrequencies,
     and corresponding ingredients for the computation of the electron-phonon effect, in the
     next tests 51-53.

 51. He BCC primitive cell. Fake smooth pseudopotential.
     Follow-up of test 50. Merge the DDB files.

 52. He BCC primitive cell. Fake smooth pseudopotential.
     Follow-up of test 50. Merge the EIGR2D files.

 53. He BCC primitive cell. Fake smooth pseudopotential.
     Follow-up of test 50. Analyse (anaddb) the DDB and EIGR2D files.
     Compute the electron-phonon modifications of the electronic structure.
     Result to be compared with test 57 and 59.
     For the lowest eigenenergy, with -0.19671 Ha, ZP correction is -1.775400E-03  (kpt 2, band 1)
     For the HOMO,               with  0.09747 Ha, ZP correction is  1.970638E-03  (kpt 1, band 1)
     For the LUMO,               with  0.46242 Ha, ZP correction is -3.291344E-03  (kpt 1, bands 2 to 4)
     Note that the k point grid is shifted, but not the q point grid.

 54. He BCC conventional cell. Fake smooth pseudopotential.
     For testing the electron-phonon modification of the electronic structure.
     To be compared with the results of tests 50 to 59.
     Use a FCC grid of k (shifted) and q (non-shifted) points.
     No imaginary frequences for the phonons with this choice.
     Computation of the electronic eigenvalues as well as phonon eigenfrequencies,
     and corresponding ingredients for the computation of the electron-phonon effect, in the
     next tests 55-57.

 55. He BCC conventional cell. Fake smooth pseudopotential.
     Follow-up of test 54. Merge the DDB files.

 56. He BCC conventional cell. Fake smooth pseudopotential.
     Follow-up of test 54. Merge the EIGR2D files.

 57. He BCC primitive cell. Fake smooth pseudopotential.
     Follow-up of test 54. Analyse (anaddb) the DDB and EIGR2D files.
     Compute the electron-phonon modifications of the electronic structure.
     Result to be compared with test 53 and 59. Agreement at the level of the sixth digit.
     For the lowest eigenenergy, with -0.19671 Ha, ZP correction is -1.775406E-03  (kpt 1, bands 1 and 2)
     For the HOMO,               with  0.09747 Ha, ZP correction is  1.970635E-03  (kpt 4, bands 1 and 2)
     For the LUMO,               with  0.46242 Ha, ZP correction is -3.291346E-03  (kpt 1, bands 3 to 8)

 58. He BCC 8-atom supercell. Fake smooth pseudopotential.
     For testing the electron-phonon modification of the electronic structure.
     To be compared with the results of tests 50 to 59.
     Use 1/2 1/2 1/2 for electronice wavevector and Gamma point for phonon wavevector
     Computation of the electronic eigenvalues as well as phonon eigenfrequencies,
     and corresponding ingredients for the computation of the electron-phonon effect, in the
     next test 59 (no need of mrgddb with only one q point.

 59. He BCC 8-atom supercell. Fake smooth pseudopotential.
     Follow-up of test 58. Analyse (anaddb) the DDB and EIGR2D files.
     Compute the electron-phonon modifications of the electronic structure.
     Result to be compared with test 53 and 57. Agreement at the level of the sixth digit.
     For the lowest eigenenergy, with -0.19671 Ha, ZP correction is -1.775401E-03  (bands 1 to 6)
     For the HOMO,               with  0.09747 Ha, ZP correction is  1.970636E-03  (bands 7 and 8)
     For the LUMO,               with  0.46242 Ha, ZP correction is -3.291344E-03  (bands 9 to 14)

 60. Crystalline Silicon
     Test the smearing parameter ESMEAR of the imaginary second order eigenvalues
     for Q-point (0 0 0), contained in the EIGI2D files. Parameters are far from
     convergence, nband=5 and nkpt=16.
     (contributed by P. Boulanger)

 61. H2 Molecule in a small box
     Second-order eigenvalue calculation using a small number of bands,
     testing bdeigrf.
     (contributed by P. Boulanger)

 62. Computation of phonons and response to electric field within PAW (both q=0 and q/=0)
     Test on AlAs structure inspired by tutorespfn/trf2 tutorial.
     Ground state is computed.
     DDK is computed.
     Dielectric tensor is computed.
     Phonon modes at q=0 are computed.
     Phonons modes at q=(1/4,0,0) and q=(-1/4,1/2/1/4) are computed.
     For the time being mixing of electric field and atomic displacement is not allowed
     (contributed by M. Torrent)

 63. Si diatomic molecule
     Test of linear and non-linear response in the non-spin-polarized case.
     Only four bands are allowed, both spin-up and spin-down, so that
     the molecule is non spin polarized.
     However nsppol=2 for testing purposes.
     Over 1200 WARNINGS.
     This test must give the same results of the test 64
     (contributed by F. Da Pieve)

 64. Si diatomic molecule
     Test of linear and non-linear response in the non-spin-polarized case.
     Only four bands are allowed, both spin-up and spin-down, so that
     the molecule is non spin polarized (with nsppol=1).
     Over 1200 WARNINGS.
     This test must give the same results of the test 63
     (contributed by F. Da Pieve)

 65. NaCl Molecule in a big box
     3DTE calculation with only one k-point
     (contributed by S. Le Roux)

 66. He dimer, with bare pseudopotential
     ixc=0
     Compute Raman intensity, showing essentially perfect agreement
     between DFPT and finite-differences, when the number of k points
     is extended to infinity.
     The present test use ngkpt 10 1 1 , giving
     DFPT : 0.039868
     Finite-differences : 1.6318415296 - 1.6216781815 = 0.0101633077
        to be divided by 0.02 (the difference in xcart) and 4pi => 0.040439
     Going to ngkpt 80 1 1 , gives :
     DFPT : 0.040052
     Finite-differences : 0.040054
     The DFPT with ngkpt 320 1 1 gives 0.040055 .

 67. Charged (He dimer)+, with bare pseudopotential
     ixc=7
     Compute Raman intensity, showing essentially perfect agreement
     between DFPT and finite-differences, when the number of k points
     is extended to infinity.
     The present test use ngkpt 10 1 1 , like the previous one.
     Going to ngkpt 80 1 1 gives
     Finite-differences : 0.022275
     The DFPT with ngkpt 320 1 1 gives 0.022279 .
     (To obtain the finite-difference results, one has to reactivate the dtset 15 case)

 68. H2 molecule in a reasonably large box
     Compute the Fan and Diagonal Debye-Waller corrections to the eigenenergies.

 69. H2 molecule in a reasonably large box
     Analysis of the test 68 results, using anaddb.

 70. VN in FCC. Phonon analysis using ANADDB.

 71. VN in FCC. Phonon analysis using ANADDB.
     Differs from test 70 by the modification of acell and rprim inside the DDB.

 72. Ground state and phonons of hcp TiNb alloy
     Test contributed by M. Verstraete

 73. mrgddb of test 72
     Test contributed by M. Verstraete

 74. mrggkk of test 72
     Test contributed by M. Verstraete

 75. mrggkk of test 72 to make auxiliary file finegrid_GKK
     Test contributed by M. Verstraete

 76. anaddb run using standard integration method
     Test contributed by M. Verstraete
     also tests the *atprj_bs variables, for atomic projections of the phonon band structure

 77. anaddb run using fine k-gird for Fermi surface integration use_k_fine
     should give identical results to 75, but does not work as yet
     Test contributed by B. Xu

 78. Generate first-order responses for FCC Aluminum.
     Very low cut-off, to keep CPU the lowest possible
     Aim at a regular sampling of phonon wavevectors, needed to
     interpolate the dynamical matrix over the whole Brillouin Zone.
     Use the definition through ngqpt and nshiftq.
     Otherwise, similar to Tv2#26

 79. Combines the DDBs of test 78.

 80. Phonon band structure of Al, from DDB of test 78.
     The parameters were really too low in test 78, so that some
     phonon unstabilities are present close to Gamma.
     Similar to Tv2#28


 81. Use output from t78 to test qrefine: trivially start with 1x1x1 q-point grid and add the 2x2x2
     q-points after the method of Gaal Nagy. Not working yet.

 85. Compute the Short-Range/Long-Range decomposition of the phonon frequencies of BaTiO3. (EB)

 89. Computation of phonons frequencies for metallic occupations at q=0 0 0 within PAW
     O2 (nsppol=1); this test is directly inspired by test v3#75.
     In datasets 1-3, one computes the total energy and forces, without symmetries,
     as it should be for accurate finite-difference tests.
     From the reduced gradients with respect to displacements, one can deduce
     a 2DTE of 149.9614 Ha.
     In dataset 4, RF is computed with the Fermi energy correction,
     and the agreement with finite-differences of datasets 1 and 3
     is good : one gets 149.9612 Ha.
     In dataset 5, RF is computed with frozen Fermi energy and the disagreement with
     finite-differences of datasets 1 and 3 is large: one gets 124.9787 Ha.
     Test contributed by M. Torrent.

 90. Ground state and phonons of hcp Ti (similar to test 72, but grid 2 2 4)
     Test contributed by M. Verstraete

 91. mrgddb of test 90
     Test contributed by M. Verstraete

 92. mrggkk of test 90
     Test contributed by M. Verstraete

 93. anaddb test electron phonon coupling with shifted fermi level of hcp Ti
     Test contributed by B. Xu

 94. anaddb test electron phonon coupling with extra number of electons of hcp Ti
     Test contributed by B. Xu


     Tests 121-126 contributed by Jiawang Hong. XG120616 : all were transferred to tests/seq. Problem of portability ...

121. PbTiO3 in the tetragonal geometry.
     Test berryopt=14 (finite reduced electric field calculation,relaxing cell 
     parameters, e.g. optcell=2)
     (XG120616 : tranferred to tests/seq)

122. PbTiO3 in the tetragonal geometry.
     Test berryopt=16 (finite reduced electric displacement field calculation,
     relaxing cell parameters, e.g. optcell=2)
     (XG120616 : tranferred to tests/seq)

123. PbTiO3 in the tetragonal geometry.
     Test berryopt=4 (finite electric field calculation, relaxing cell 
     parameters, e.g. optcell=2)
     (XG120616 : tranferred to tests/seq)

124. PbTiO3 in the tetragonal geometry.
     Test berryopt=6 (finite electric displacement field calculation,
     relaxing cell perameters, e.g. optcell=2)
     (XG120616 : tranferred to tests/seq)

125. Test berryopt=17 (mixed finite electric field and electric displacement 
     field boundary condition, relaxing cell parameters, e.g. optcell=2)
     (XG120616 : tranferred to tests/seq)

126. AlAs case, to test the "polcen" in finite reduced electric field calculation. 
     (XG120616 : tranferred to tests/seq)

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