Dear APBS Users --

APBS 1.2.1 has been released.  This is a bugfix release specifically aimed at addressing a problem with certain nonlinear Poisson-Boltzmann calculations.  In particular, several users noticed that Poisson-Boltzmann calculations which focused into a low dielectric region would occasionally generate very large (~1E25 kJ/mol) energies.  This was due to a bug that caused instability in the nonlinear Poisson-Boltzmann solver.  This bug has been fixed in this release.

The full list of changes is:
    • Added in warning into focusFillBound if there is a large value detected in setting the boundary conditions during a focusing calculation
    • Added in a check and abort in Vpmg_qmEnergy if chopped values are detected. This occurs under certain conditions for NPBE calculations where focusing cuts into a low-dielectric regions.
    • Fixed a bug in Vpmg_MolIon that causes npbe based calculations to return very large energies.  This occurs under certain conditions for NPBE calculations where focusing cuts into a low-dielectric regions.

More information about APBS as well as download links can be obtained from http://www.poissonboltzmann.org/.

We apologize for this bug and thank you for your continued support of APBS.

Sincerely,

The APBS Development Team