[ESPResSo] DPD and velocity verlet integration

[Jacob Kirkensgaard]

Hello

I am implementing some DPD polymer simulations and would like to use  
the modified velocity-Verlet (VV) algorith used by Groot and Warren in
Groot and Warren, J. Chem. Phys. 107 (11) 1997. I attach a snapshot of  
the equations:

As is stated the usual VV is recovered for lambda = 0.5. The  
documentation is close to non-existing on this matter so here are the  
questions:

1: Does the implemented version of the VV include the 0.5*Delta t^2  
term in the first step? This is shown in the above paper to be crucial  
to temperature control in DPD. There is mentioning of some scaling of  
the forces in the code (integrate.c) but I am unsure if it means  
exactly this...

2: I suspect the lambda thing is NOT implemented in Espressos version  
of the VV - does anyone know?

Kind regards and thanks,
Jacob