Release notes

##### Copyright (C) 2009-2021 ABINIT group (XG)
This file is distributed under the terms of the GNU General Public License, see ~abinit/COPYING or http://www.gnu.org/copyleft/gpl.txt .
For the initials of contributors, see ~abinit/doc/developers/contributors.txt .

    Many thanks to the contributors to the ABINIT project
    between September 2008 and January 2009. These release notes
    are relative to improvements of ABINITv5.7 with respect to v5.6.

    The list of contributors includes :
    D. Berkholz, F. Bottin, F. Bruneval, D. Caliste, M. Delaveau, T. Deutsch, G.A. Franco, M. Giantomassi,
    D. Hamann, A. Jacques, A. Lherbier, M. Oliveira, M. Mancini, M. Marques, M. Mikami,
    H. Peelaers, Y. Pouillon, T. Rangel, G.-M. Rignanese, L. Sindic, M. stankowski,
    M. Torrent, M. Verstraete, G. Zerah, Zhenhua Zeng, J. Zwanziger

    It is worth to read carefully
    all the modifications that are mentioned in the present file,
    and examine the links to help files or test cases ...
    This might take some time ...
    Please note the WARNINGS !

    Xavier

    __________________________________________________________________

    Version 5.7, released on January 10, 2009.

    Changes with respect to version 5.6 :

    A. WARNINGS.
    B. Most noticeable achievements (for users)
    C. Changes in the package, for developers
    D. Other changes (or on-going developments, not finalized)

    __________________________________________________________________

    A.  WARNINGS

    A.1 The content of tests paral M, N, and R has changed, to decrease the CPU time needed for them.

    __________________________________________________________________

    B.  Most noticeable achievements

    B.1 The ETSF LibXC, from Miguel Marques, can now be used in production.
        See the input variable ixc, as well as the automatic tests provided
        in tests/etsf_xc . This library is a plug-in to ABINIT, and in order to benefit
        from the LibXC, the user must have build ABINIT with the enable etsf-xc flag.
        The LibXC (version 0.9 as of December 2008) comes with 16 functional forms of the LDA type,
        and 41 functional forms of the GGA type. It is also an important step towards
        using hybrids and meta-GGAs.
        At present the LibXC cannot be used for response function calculations.
        The interfacing with ABINIT has been done by M. Oliveira and Y. Pouillon.

    B.2 The Wannier90 interpolation of band structure can be used to interpolate
        self-consistent GW calculations. See test Wannier90#03.
        Work done by Tonatiuh Rangel, Don Hamann, Matteo Giantomassi, Gian-Marco Rignanese.
        However, the testing procedure is still rather incomplete. Only the .out is tested.
        Wannier90 tutorial has been improved

    B.3 Implemented broadening of the electronic states due to interaction with phonon (electronic lifetime).
        Use of the tetrahedron method to produce the phonon DOS, as well as the
        temperature dependence of the electronic structure (including the gap).
        Work by P. Boulanger. See the input variable smdelta in anaddb.
        Test and doc to be provided. Note independent work by M. Giantomassi on the phonon DOS.

    B.4. Large improvement of the band FFT parallelism by M. Delaveau and F. Bottin.
        In particular, solved many problems with preconditioning,
        ability to write in parallel the binary files, in an efficient way,
        using MPI OI, implementation of restart within LOBPCG in order to avoid crash during the minimization.
        Introduction of the cpp directive MPI_IO_MORE.

    B.5 Spin generalisation (nspden=2, 4) of the ability to compute the Fermi contact interaction at each nuclear
        site, as well as to compute the electric field gradient  by Joe Zwanziger.
        See new test v5#36, as well as updated test v5#34.

    __________________________________________________________________

    C. Changes for the developers

    C.1 The robustness of the build system (bug fixing) has been
        improved a lot by Y. Pouillon . Also, several problems have been
        observed, isolated, fixed by Y. Pouillon, J.-M. Beuken, D. Caliste and A. Jacques.

    C.2 Restructuring of the set of source directories. In particular, the interfaces*F90 files
        are now generated in a separate directory.

    C.3 Constitution of several modules, gathering coherent sets of smaller routines, by Matteo Giantomassi.

    C.4 Enable user-specified Fortran compiler vendor and version by Y. Pouillon

    C.5 Added build-system support for the PAPI library, added --enable-mpi-io-buggy option,
        added the support for modules, worked on Scalapack support.
        By Y. Pouillon

    C.6 Print the information about the build, the compilation, bazaar branch, etc, inside the log file.
        Work by Y. Pouillon.

    __________________________________________________________________

    D.  Other changes
    (or on-going developments, not yet finalized).

    D.1 Ability to compute the characters of the symmetries applied to electronic states,
         to find irreducible representations, by M. Giantomassi. No test available yet.

    D.2 Ability to compute the Fermi contact interaction at each nuclear
        site has been extended to the spin-dependent case, by Joe Zwanziger.
        See test v5#36.

    D.3 Ability to mix separately the magnetization from the density
        in the PAW scheme, see the input variable diemixmag, by M. Torrent.
        See test v5#16.

    D.4 Ability to output the full physical density in PAW, using the input variable pawprtden.
        Work by J. Zwanziger, some help by M. Torrent.

    D.5 Preservation of symmetry when optcell 2 for body tetragonal lattice,
        see test v5#37.
        Bug fix by Joe Zwanziger

    D.6 Maintenance work on abilint by T. Deutsch, fix of small problems, and followed the
        evolution of the build system.

    D.7 Work on LDA+U+GW, also non-collinear spin and spin-orbit by M. Giantomassi.
        Possibility to restart a sigma calculation from a SUSC file using mqmem==0,
        see automatic test v5#70.

    D.8 Improvement of the direct computation
        of the density based on the recursion method (instead of the
        iterative determination of the eigenfunctions) : use of two grids (to speed up the calculation)
        Introduction of the new input variables recgratio.
        Still to be documented.
        Work by Marco Mancini and Gilles Zerah.

    D.9. Suggestions for acknowledgments are now automatically generated, at the end of the output file.

    D.10 Memory saving for Godby-Needs plasmon-pole model, by F. Bruneval

    D.11. Introduced new input variable irdden, by F. Bruneval. (COMMENT : seem to be disabled ?!)

    D.12 Introduced short-range-only Coulomb interaction 'ERFC',k by F. Bruneval. No automatic test, not documented.

    D.12 Improvements in BigDFT by D. Caliste. Introduction of the BigDFT 1.2.
         To be documented.

    D.13 Restart of of SCF mixing for PAW+U

    D.14 X Spectroscopy implemented by S. Mazevet.

    D.15 Modified paw routines to be compatible with complex rhoij, for the PAW spin orbit case,
         introduction of the new input variable pawcpxocc, by M. Torrent and J. Zwanziger

    D.16. Introduction of the new input variable spnorbscl, to be able to scale the strength
        of the spin-orbit interaction for PAW with spin-orbit. Work by Micael Oliveira.
        No test available yet, not documented.

    D.17 Work on magnetic response by J. Zwanziger.

    D.18 In addition, miscellaneous bug fixes by many developers (see the list of contributors),
         many bug fixes in documentation, ...