Feature #3417: Make modular simulator feature-complete
Implement stochastic dynamics / langevin integrator in modular simulator
Unlike GROMACS 2020, GROMACS 2021 should have the
sd integrator available in modular simulator.
We are planning on implementing the framework presented be Leimkuhler et al. (https://aip.scitation.org/doi/10.1063/1.4802990, also discussed in https://pubs.acs.org/doi/abs/10.1021/jp411770f). Note that this would not just be a SINGLE Langevin integrator, but the framework to swap around orders of the different steps (velocity/position/Ornstein-Uhlenbeck process), so that a number of different algorithms could be implemented easily.
So part of this task is to understand whether we need a new integrator flag, and which scheme the current
integrator = sd flag should call.