Custom Forces on Multiple GPUs

[anisha-yeddanapudi]

Hi,
I'm trying to run a simulation with custom external forces on multiple GPUs (mpirun), at the moment I have the following code:

if self.device=='cpu':
            with self.cpu_local_force_arrays as force_arrays:
                with self._state.cpu_local_snapshot as snap:
                    forces = EForce(snap.particles.position, snap.particles.charge, self.L)
                    force_arrays.force[:] = forces
elif self.device =='gpu':
            with self.gpu_local_force_arrays as force_arrays:
                with self._state.gpu_local_snapshot as snap:
                    forces = EForce(snap.particles.position, snap.particles.charge, self.L)
                    force_arrays.force[:] = cupy.array(forces)

I was wondering if this is the correct way to reassign the HOOMDGPUArray object and incorporate the custom external force into the simulation (in addition to the other forces present) as such:

integrator.forces.append(lj)
integrator.forces.append(morse)
if external_drive == True:
            ex_drive = MyCustomForce()
            integrator.forces.append(ex_drive)

Thanks!

[joaander]

This looks reasonable.