Dear Colleague,

Two bugs have been discovered in the Dissipative Particle Dynamics (DPD) code of 
DL_MESO version 2.6.

When running systems without many-body DPD calculations, a division by zero may 
result if the many-body cutoff distance is not specified in the CONTROL file. 
While this division is not critical for simulations without many-body DPD 
interactions, certain compilers and compilation flags may cause the code to stop 
due to a runtime error. To fix this bug, change line 141 in config_module.f90 
to:

  IF (lmb) rrmbcut = 1.0_dp / rmbcut

A bug has also been spotted when running simulations with the Peters thermostat 
coupled to the Langevin barostat: as the code currently stands, incorrect stress 
tensors will be calculated for systems with frozen beads when the code is run in 
parallel. To fix this bug, change lines 686, 947 and 1259 in 
integrate_peters.f90 to:

  DO i = nfbeads+1, nbeads

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
2017-02-07