The AdResS object is an extension to the integrator. It makes sure that the integrator also processes the atomistic particles and not only the CG particles. Hence, this object is of course only used when performing AdResS or H-AdResS simulations.

In detail the AdResS extension makes sure:

• that also the forces on the atomistic particles are initialized and set to by Adress::initForces
• that also the atomistic particles are integrated and propagated by Adress::integrate1 and Adress::integrate2

Example - how to turn on the AdResS integrator extension:

>>> adress = espressopp.integrator.Adress(system, verletlist, fixedtuplelist)


Finally, when making use of a RESPA Velocity Verlet integrator, then the multistep parameter defines after how many steps of the inner integration loop the slow forces are updated. It should be set consistently with the same parameter in VelocityVerletRESPA.

class espressopp.integrator.Adress(_system, _verletlist, _fixedtuplelist, KTI, regionupdates, multistep)
Parameters: _system (shared_ptr) – system object _verletlist (shared_ptr) – verletlist object _fixedtuplelist (shared_ptr) – fixedtuplelist object KTI (bool) – (default: False) update resolution parameter? (Yes: set False, No: set True) regionupdates (int) – (default: 1) after how many steps does the AdResS region needs to be updated? multistep (int) – (default: 1) when used with VelocityVerletRESPA (otherwise, ignored), after how many steps of the inner integration loop do we update the slow forces? This parameter should be set consistently with multistep in VelocityVerletRESPA.