Merge pull request #1825 from glotzerlab/fix-brownian-torque

fix Brownian integrators when using anisotropic interactions and zeroing out elements of the moment of inertia tensor
glotzerlab · Jun 27, 2024 · 6297fb3 · 6297fb3
2 parents 9f19af0 + a1d7435
commit 6297fb3
Show file tree

Hide file tree

Showing 4 changed files with 36 additions and 0 deletions.
diff --git a/hoomd/md/TwoStepBD.cc b/hoomd/md/TwoStepBD.cc
@@ -182,11 +182,20 @@ void TwoStepBD::integrateStepOne(uint64_t timestep)
                 bf_torque.z = NormalDistribution<Scalar>(sigma_r.z)(rng);
 
                 if (x_zero)
+                    {
                     bf_torque.x = 0;
+                    t.x = 0;
+                    }
                 if (y_zero)
+                    {
                     bf_torque.y = 0;
+                    t.y = 0;
+                    }
                 if (z_zero)
+                    {
                     bf_torque.z = 0;
+                    t.z = 0;
+                    }
 
                 // use the damping by gamma_r and rotate back to lab frame
                 // Notes For the Future: take special care when have anisotropic gamma_r

diff --git a/hoomd/md/TwoStepBDGPU.cu b/hoomd/md/TwoStepBDGPU.cu
@@ -233,11 +233,20 @@ __global__ void gpu_brownian_step_one_kernel(Scalar4* d_pos,
                 bf_torque.z = NormalDistribution<Scalar>(sigma_r.z)(rng);
 
                 if (x_zero)
+                    {
                     bf_torque.x = 0;
+                    t.x = 0;
+                    }
                 if (y_zero)
+                    {
                     bf_torque.y = 0;
+                    t.y = 0;
+                    }
                 if (z_zero)
+                    {
                     bf_torque.z = 0;
+                    t.z = 0;
+                    }
 
                 // use the damping by gamma_r and rotate back to lab frame
                 // For Future Updates: take special care when have anisotropic gamma_r

diff --git a/hoomd/md/TwoStepRATTLEBD.h b/hoomd/md/TwoStepRATTLEBD.h
@@ -331,11 +331,20 @@ template<class Manifold> void TwoStepRATTLEBD<Manifold>::integrateStepOne(uint64
                 bf_torque.z = NormalDistribution<Scalar>(sigma_r.z)(rng);
 
                 if (x_zero)
+                    {
                     bf_torque.x = 0;
+                    t.x = 0;
+                    }
                 if (y_zero)
+                    {
                     bf_torque.y = 0;
+                    t.y = 0;
+                    }
                 if (z_zero)
+                    {
                     bf_torque.z = 0;
+                    t.z = 0;
+                    }
 
                 // use the d_invamping by gamma_r and rotate back to lab frame
                 // Notes For the Future: take special care when have anisotropic gamma_r

diff --git a/hoomd/md/TwoStepRATTLEBDGPU.cuh b/hoomd/md/TwoStepRATTLEBDGPU.cuh
@@ -291,11 +291,20 @@ __global__ void gpu_rattle_brownian_step_one_kernel(Scalar4* d_pos,
                 bf_torque.z = NormalDistribution<Scalar>(sigma_r.z)(rng);
 
                 if (x_zero)
+                    {
                     bf_torque.x = 0;
+                    t.x = 0;
+                    }
                 if (y_zero)
+                    {
                     bf_torque.y = 0;
+                    t.y = 0;
+                    }
                 if (z_zero)
+                    {
                     bf_torque.z = 0;
+                    t.z = 0;
+                    }
 
                 // use the damping by gamma_r and rotate back to lab frame
                 // For Future Updates: take special care when have anisotropic gamma_r