Release notes

##### Copyright (C) 2010-2021 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
    September 2010 and February 2011. These release notes
    are relative to improvements of ABINITv6.6 with respect to v6.4.

    The list of contributors includes :
    D. Adams, B. Amadon, A. Berger, J.-M. Beuken, F. Bottin,
    P. Boulanger, F. Bruneval, D. Caliste, M. Delaveau, C. Espejo, Don Fanucci,
    G.A. Franco, M. Giantomassi, X. Gonze, I. Hamada, N. Holzwarth, A. Jacques, F. Jollet, S. Le Roux,
    A. Lherbier, M. Mancini, T. Nishimatsu, M. Oliveira, S. Ponce, Y. Pouillon,
    P.-Y. Prodhomme, M. Rampp, T. Rangel,
    G.-M. Rignanese, AH Romero, M. Stankovski, M. Torrent, M. Verstraete, D. Waroquiers,
    Z. Zanolli, 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 6.6, released on February 7, 2011.

    Changes with respect to version 6.4 :

    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 AND IMPORTANT REMARKS

    A.1 The user interface of the build system has changed.
        The plugins are currently being replaced by a mechanism of
        connectors / fallbacks. As a consequence, a few options of the
        configure script have changed:
          - a new --with-dft-flavor option allows for the detection and
            possible build of AtomPAW, BigDFT, LibXC, and Wannier90;
          - a new --with-trio-flavor option allows for the detection and
            possible build of ETSF_IO, FoX, and NetCDF;
          - the --enable-* options related to the above plugins have been
            removed, but their --with-* options have been kept;
          - the --enable-all-plugins has been removed, and its former
            outcome can be reproduced by using both:
              --with-dft-flavor="atompaw+bigdft+libxc+wannier90"
              --with-trio-flavor="etsf_io+fox+netcdf"
            or by setting these two options to "none" to disable all
            plugins.
        Please have a look at ~abinit/doc/build/config-template.ac for
        complete details. The output of configure contains as well useful
        information about changed options at its beginning.
        In order to facilitate the transition, you'll find the
        extras/build/upgrade-build-config script. Call it using -h or --help
        for documentation.

    __________________________________________________________________

    B.  Most noticeable achievements

    B.1 The PAW atomic dataset generator ATOMPAW, from Natalie Holzwarth and coworkers,
        has been adapted as a plugin for ABINIT. The interface with ABINIT is tested
        automatically, thanks to tests in tests/atompaw.
        ATOMPAW compiles correctly on all the standard testing platforms of ABINIT,
        so that it is considered as being part of the
        standard reference configuration of the ABINIT package.
        The executable is generated in plugins/atompaw .
        Also, the ability to use libxc with atompaw is present, and the pseudopotentials that have
        been generated can be used without mentioning the ixc value (that is passed to
        ABINIT transparently for the user).
        Tests are tests/atompaw #01 and #02 (generation of the PAW dataset by PAW then use by ABINIT),
        and tests/libxc #10 (use of a PAW dataset for PBEsol).
        Plugin set-up and interfacing with ABINIT
        done by Yann Pouillon, Jean-Michel Beuken, Marc Torrent, Joe Zwanziger and XG, in collaboration
        with N. Holzwarth.
        ATOMPAW from Natalie Holzwarth and Alan Tackett.

    B.2 Two new tutorials are available :
        - lesson_detu.html, for the determination of the U and J values from the method by Coccochioni and de Gironcoli
             (see the release_notes of v6.4, section B.4, for the announcement of the related input variables and automatic tests).
        - lesson_paw3.html, for the testing of Atomic dataset, compared to the ELK code.
        Work by D. Adams and B. Amadon (for the U+J tutorial), and M. Stankovski for the PAW3 tutorial.

    B.3 The usage of MPIIO can be now considered in production for the FFT/Band parallelism of ABINIT.
        Automatic tests in tests/mpiio have been shown to work on all platforms of the ABINIT test farm,
        except with the pathscale compiler, and under Windows.
        Build system tuning, and then testing by Y. Pouillon, Jean-Michel Beuken, M. Giantomassi, XG.
        Initial MPIIO implementation by M. Boulet, F. Bottin and G. Zerah, improved by M. Delaveau and M. Torrent.

    B.4 The plasmon-pole models 2-3-4 can now be used in GW+PAW.
        By M. Giantomassi

    __________________________________________________________________

    C. Changes for the developers

    C.1 Max and littlebuda are two new slaves for the test farm :
        - max tests the parallelism up to 10 procs using Myrinet;
        - littlebuda tests the compilation and links with GPU turned on. No tests activated yet, though.
        By J.-M. Beuken, Y. Pouillon, X. Gonze

    C.2 Build systems tests have been set-up . They are activated on the "inca" slave.
        By Y. Pouillon.

    __________________________________________________________________

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

    D.1 The two-phonon DOS sum and difference spectra can now be computed.
        See test v2#15.
        By A. Romero.

    D.2 Analysis of GW wavefunctions with cut3d now possible
        By F. Bruneval

    D.3 The capability to split the generation of dielectric matrices for the contour deformation GW technique
        in different bunches of frequencies has been implemented, allowing a much better flexibility.
        Then they can be merged using mrgscr .
        Related input variable : freqremin.
        Work by M. Stankovski and M. Giantomassi.

    D.4 The input variable esmear has been defined, to be used for the computation of electron lifetimes.
        Test v6#60.
        By P. Boulanger.

    D.5 Capability to output the total PAW density on the fine grid has been improved (parallelism).
        By M. Stankovski and J. Zwanziger.

    D.6 Libxc 1.0 is now used.
        Upgrade for ABINIT was done by Y. Pouillon

    D.7 ANADDB uses now much less memory for computation of the temperature dependence of the electronic structure.
         By S. Ponce

    D.8 On-going big restructuration of the routines involved in the change
        of the atomic coordinates and cell parameters (called by gstate.F90, linke brdmin.F90), also coupled with on-going
        changes to accomodate the images (above gstate.F90).
        Defines the use of NETCDF files, also ETSF-IO , for the restarts.
        See section C.3 of v6.4 release notes.
        By G.A. Franco .

    D.9 On-going large improvement of the parallelism for GW, including MPIIO,
        also based on the standard _WFK files,
        by M. Giantomassi, with testing done at the Barcelona Supercomputing Center by G. Huhs (formerly A. Soba),
        and M. Stankovski, D. Waroquiers, G.-M. Rignanese and XG.

    D.10 The use of Density Functional Perturbation Theory with PAW
         (phonons and electric field) is in progress,
         See section D.2 of v6.4 release notes.
         by M. Torrent, F. Jollet and J. Zwanziger.

    D.11 The use of an extrapolation scheme to decrease the number of k-points needed for Berry phase
         calculations, finite electric fields and Raman intensity is in progress.
         Test v6#20 . Input variable berrystep.
         By S. Le Roux.

    D.12 Work in progress concerning the EET method for GW calculations.
         By A. Berger.

    D.13 GW numerous small improvements. Also, working on the intraband contrib.
         By M. Giantomassi

    D.14 The use of LDA+Dynamical Mean Field Theory is in progress.
         (see D.6 of the 6.4 release notes)
         Test v6#51.
         A new input variable "dmft_dc" has been introduced.
         By B. Amadon

    D.15 Work in progress for the implementation of the Path Integral Molecular Dynamics algorithm for the
         ionic degrees of freedom, combined with DFT for the electronic degrees of freedom.
         Input variable pitransform
         Allowed by imgmov=9 (Langevin dynamics), imgmov=13 (chain of thermostats).
         Test (fake at present) : Tv6#26
         (see D.7 of the 6.4 release notes)
         No merge with the trunk at present.
         By G. Geneste and X. Gonze.

    D.16 On-going effort to provide vdW functionals for ABINIT.
         Silvestrelli approach is working.
         See input variables vdw_xc (=10 for Silvestrelli approach), vdw_nwan and vdw_supercell .
         Also, the XC functional C09 (ixc 24), for use with the Silvestrelli approach, has been coded.
         Available in v6#12, 13.
         Also, a new directory to test vdwxc has been created. At present Tvdwxc#10 is working.
         (see D.7 of the 6.4 release notes)
         Work by C. Espejo, Y. Pouillon, AH. Romero and X. Gonze.

    D.17 On going effort to have all mGGA from Libxc available.
         By M. Oliveira, A. Lherbier and X. Gonze.

    D.18 Work in progress : addition of Zeeman field (non-collinear), using the zeemanfield
         input variable. The documentation of the latter is still incomplete.
         A fake test has been set up v6#17.
         (see D.11 of the 6.4 release notes)
         By K. Delaney and E. Bousquet.

    D.19 A slave for the production of .exe for Windows is nearly operational.
         The tests of the FFTW3 library are in progress.

    D.20 A genetic algorithm to find new structures is under development.
         (see D.13 of the 6.4 release notes)
         By AH. Romero and X. Gonze

    D.21 New input variables for the file handling (restart) in the BSE case have been defined :
         getbsreso, getbscoup, gethaydock, irdbscoup, irdbsreso, irdhaydock .
         Other improvements for BSE : BSE+Spin, use of model dielectric functions,
         DOS calculations with Haydock. CG algo for resonant BSE calculations.
         MPI-IO+scalapack capabilities.
         Generalized eigenvalue problem for BSE with coupling (more stable, can use Scalapack)
         By M. Giantomassi.

    D.22 New input variables, undocumented : use_slk. Likely from F. Bottin. Related to scalapack.

    D.23 On-going work on the link of the XC kernels from libxc to ABINIT.
         By F. Liu, L. He and G.-M. Rignanese .

    D.24 Work on SCPhonons going on.
         By M. Verstraete

    D.25 Numerous miscellaneous bug fixes (to the sources, as well as to the build system, including the plug-ins),
         and improvements of documentation by
         B. Amadon, A. Berger, J.-M. Beuken, D. Caliste, Don Fanucci,
         G.A. Franco, M. Giantomassi, X. Gonze, I. Hamada, A. Jacques, F. Jollet, S. Le Roux,
         A. Lherbier, M. Mancini, T. Nishimatsu, S. Ponce, Y. Pouillon, P.-Y. Prodhomme, M. Rampp, T. Rangel,
         G.-M. Rignanese, M. Torrent, M. Stankovski, M. Verstraete, Z. Zanolli, J. Zwanziger .