ESPResSo 4.0.2 released

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 

Get it in the Download area

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).