Dear Colleague,

Three bugs have been spotted in DL_MESO version 2.6: two in the Dissipative 
Particle Dynamics (DPD) and one in the Lattice Boltzmann Equation (LBE) code.

As the DPD code currently stands, it cannot correctly read in the parameters 
from the CONTROL file for constant stress ensembles with the Berendsen barostat, 
nor distinguish between ensembles that set constant surface areas, surface 
tensions and semi-isotropic changes to the system volume. This is due to a bug 
in reading the ensemble directive in the CONTROL file.

To fix this bug, the calls to the functions getdble and getword in lines 1050, 
1053, 1058, 1059, 1063, 1069, 1072, 1077, 1078 and 1082 of config_module.f90 
need to be modified by increasing the second argument by 1, so they read 
(respectively):

  abaro = getdble (record, 6)
  word3 = getword (record, 7)
  bbaro = getdble (record, 8)
  word4 = getword (record, 9)
  word4 = getword (record, 8)
  abaro = getdble (record, 5)
  word3 = getword (record, 6)
  bbaro = getdble (record, 7)
  word4 = getword (record, 8)
  word4 = getword (record, 7)

When applying a constant surface area ensemble using the Langevin barostat with 
the DPD thermostat and standard (MD) Velocity Verlet integration, an array 
deallocation error will occur. This is due to the existence of an extraneous, 
unallocated and unused array defined for this ensemble. To fix this bug, change 
line 431 in integrate_dpd_mdvv.f90 to:

  REAL(KIND=dp), ALLOCATABLE :: ovz (:)

and line 621 in the same module to:

  DEALLOCATE (ovz, STAT=fail)

The constant density/pressure boundary condition in the LBE code is currently 
applied incorrectly for systems with two-fluid Swift-based free-energy 
interactions. To fix this bug, change line 2842 in lbpBOUND.cpp to:

  f2[1]=p[1]*(1.0+c3*vel)-f0[1]-f1[1]-f3[1]-f6[1]-f7[1]-f10[1]-f11[1]-f12[1]-f15[1]-f16[1]-2.0*(f5[1]+f13[1]+f17[1]+f18[1]);

We strongly recommend that all registered users of DL_MESO version 2.6 should 
either make the above code changes or re-download the package using the 
instructions received on registration to get the corrected version of the 
software. Re-registration is not required and the same password is used for 
decryption.

Michael Seaton
2016-11-29