[ESPResSo-users] Espresso 4.0.2 released

[Jean-Noël Grad]

Dear Espresso users,

the Espresso team is pleased to announce the release of Espresso 4.0.2. 
The source can be downloaded at 
https://github.com/espressomd/espresso/releases/download/4.0.2/espresso-4.0.2.tar.gz
Please see the release notes below.


Many thanks to all contributors!
Regards, Jean-Noël


=================
This release provides a number of corrections for the Espresso 4.0 line.
We recommend that this release be used for all production simulations.
Please note that a sign error in tabulated interactions was fixed.
Simulation scripts which worked around this problem might have to be
changed. Below, please find the list of changes. The numbers in brackets
refer to ticket numbers on http://github.com/espressomd/espresso


Corrections for bugs that may harm simulation results:
  * A sign error in tabulated interactions was corrected such that
    the force equals the negative gradient of the potential.
    (#2519,2520)

  * The flow field of the CPU lattice-Boltzmann implementation was
    deleted when aspects of the molecular dynamics cell grid were
    changed; E.g., when interactions, the skin or the parallelization
    setup were changed. ESPResSo now terminates with an error, when this
    happens. To avoid this, please setup the CPU lattice-Boltzmann after
    all other aspects of the system. The GPU LB is not affected in the
    4.0 release, but was affected in the current development branch.
    (#2728, #2736)

  * Corrected the force acting on LB Boundaries for the case of
    agrid and density not equal to 1 (#2624).

  * Corrected the cutoff calculation for the soft sphere interaction. In
    the previous implementation, the offset parameter was ignored.
    (#2505)

  * The "three point coupling" of particles to the lattice-Boltzmann
    method has been removed. While it works in most environments, for
    some compilers the calculation gives wrong values. This is likely
    caused by undefined behavior. A corrected implementation is
    available in ESPResSo's development branch. It cannot be safely
    backported to 4.0.2, because the code has diverged too far. (#2516,
    #2517) Users who did not explicitly activate this coupling via
    couple="3pt" are not affected.

  * The velocity of existing particles was changed when setting or
    changing the simulation time step (#2480)


Further changes:
  * Fixed the electrokinetic Python interface (#2486)

  * Correction to the installation instructions for mac (#2510)

  * Corrected file permissions (#2470)

  * Minor corrections and extensions to the test suite (#2477, #2552)

  * Fixed a dead-lock in the dipolar Barnes Hutt method on the GPU for
    recent NVIDIA cards such as RTX 2080 (#2719).

  * Restored Mayavi visualizer's API-compatibility with OpenGL
    visualizer (#2751)