diff --git a/src/core/electrostatics_magnetostatics/p3m-common.cpp b/src/core/electrostatics_magnetostatics/p3m-common.cpp
index c49ed644c37..359cdd241ed 100644
--- a/src/core/electrostatics_magnetostatics/p3m-common.cpp
+++ b/src/core/electrostatics_magnetostatics/p3m-common.cpp
@@ -278,4 +278,88 @@ double p3m_caf(int i, double x, int cao_value) {
   }
   }
 }
+
+void p3m_calc_local_ca_mesh(p3m_local_mesh &local_mesh,
+                            const P3MParameters &params,
+                            const LocalBox<double> &local_geo, double skin) {
+  int i;
+  int ind[3];
+  /* total skin size */
+  double full_skin[3];
+
+  for (i = 0; i < 3; i++)
+    full_skin[i] = params.cao_cut[i] + skin + params.additional_mesh[i];
+
+  /* inner left down grid point (global index) */
+  for (i = 0; i < 3; i++)
+    local_mesh.in_ld[i] =
+        (int)ceil(local_geo.my_left()[i] * params.ai[i] - params.mesh_off[i]);
+  /* inner up right grid point (global index) */
+  for (i = 0; i < 3; i++)
+    local_mesh.in_ur[i] =
+        (int)floor(local_geo.my_right()[i] * params.ai[i] - params.mesh_off[i]);
+
+  /* correct roundoff errors at boundary */
+  for (i = 0; i < 3; i++) {
+    if ((local_geo.my_right()[i] * params.ai[i] - params.mesh_off[i]) -
+            local_mesh.in_ur[i] <
+        ROUND_ERROR_PREC)
+      local_mesh.in_ur[i]--;
+    if (1.0 + (local_geo.my_left()[i] * params.ai[i] - params.mesh_off[i]) -
+            local_mesh.in_ld[i] <
+        ROUND_ERROR_PREC)
+      local_mesh.in_ld[i]--;
+  }
+  /* inner grid dimensions */
+  for (i = 0; i < 3; i++)
+    local_mesh.inner[i] = local_mesh.in_ur[i] - local_mesh.in_ld[i] + 1;
+  /* index of left down grid point in global mesh */
+  for (i = 0; i < 3; i++)
+    local_mesh.ld_ind[i] =
+        (int)ceil((local_geo.my_left()[i] - full_skin[i]) * params.ai[i] -
+                  params.mesh_off[i]);
+  /* left down margin */
+  for (i = 0; i < 3; i++)
+    local_mesh.margin[i * 2] = local_mesh.in_ld[i] - local_mesh.ld_ind[i];
+  /* up right grid point */
+  for (i = 0; i < 3; i++)
+    ind[i] =
+        (int)floor((local_geo.my_right()[i] + full_skin[i]) * params.ai[i] -
+                   params.mesh_off[i]);
+  /* correct roundoff errors at up right boundary */
+  for (i = 0; i < 3; i++)
+    if (((local_geo.my_right()[i] + full_skin[i]) * params.ai[i] -
+         params.mesh_off[i]) -
+            ind[i] ==
+        0)
+      ind[i]--;
+  /* up right margin */
+  for (i = 0; i < 3; i++)
+    local_mesh.margin[(i * 2) + 1] = ind[i] - local_mesh.in_ur[i];
+
+  /* grid dimension */
+  local_mesh.size = 1;
+  for (i = 0; i < 3; i++) {
+    local_mesh.dim[i] = ind[i] - local_mesh.ld_ind[i] + 1;
+    local_mesh.size *= local_mesh.dim[i];
+  }
+  /* reduce inner grid indices from global to local */
+  for (i = 0; i < 3; i++)
+    local_mesh.in_ld[i] = local_mesh.margin[i * 2];
+  for (i = 0; i < 3; i++)
+    local_mesh.in_ur[i] = local_mesh.margin[i * 2] + local_mesh.inner[i];
+
+  local_mesh.q_2_off = local_mesh.dim[2] - params.cao;
+  local_mesh.q_21_off = local_mesh.dim[2] * (local_mesh.dim[1] - params.cao);
+}
+
+void p3m_calc_lm_ld_pos(p3m_local_mesh &local_mesh,
+                        const P3MParameters &params) {
+  /* spatial position of left down mesh point */
+  for (int i = 0; i < 3; i++) {
+    local_mesh.ld_pos[i] =
+        (local_mesh.ld_ind[i] + params.mesh_off[i]) * params.a[i];
+  }
+}
+
 #endif /* defined(P3M) || defined(DP3M) */
diff --git a/src/core/electrostatics_magnetostatics/p3m-common.hpp b/src/core/electrostatics_magnetostatics/p3m-common.hpp
index 0bf0e358060..f29fa76b726 100644
--- a/src/core/electrostatics_magnetostatics/p3m-common.hpp
+++ b/src/core/electrostatics_magnetostatics/p3m-common.hpp
@@ -36,6 +36,8 @@
 
 #if defined(P3M) || defined(DP3M)
 
+#include "LocalBox.hpp"
+
 /** Error Codes for p3m tuning (version 2) */
 enum P3M_TUNE_ERROR {
   /** force evaluation failed */
@@ -176,6 +178,23 @@ double p3m_analytic_cotangent_sum(int n, double mesh_i, int cao);
  */
 double p3m_caf(int i, double x, int cao_value);
 
+/** Calculate properties of the local FFT mesh for the
+ *   charge assignment process.
+ */
+void p3m_calc_local_ca_mesh(p3m_local_mesh &local_mesh,
+                            const P3MParameters &params,
+                            const LocalBox<double> &local_geo, double skin);
+
+/** Calculate the spatial position of the left down mesh
+ *  point of the local mesh, to be stored in
+ *  @ref p3m_local_mesh::ld_pos "ld_pos".
+ *
+ *  Function called by @ref p3m_calc_local_ca_mesh() once and by
+ *  @ref p3m_scaleby_box_l() whenever the box size changes.
+ */
+void p3m_calc_lm_ld_pos(p3m_local_mesh &local_mesh,
+                        const P3MParameters &params);
+
 #endif /* P3M || DP3M */
 
 #endif /* _P3M_COMMON_H */
diff --git a/src/core/electrostatics_magnetostatics/p3m-dipolar.cpp b/src/core/electrostatics_magnetostatics/p3m-dipolar.cpp
index 888d4269b86..12c57f9e910 100644
--- a/src/core/electrostatics_magnetostatics/p3m-dipolar.cpp
+++ b/src/core/electrostatics_magnetostatics/p3m-dipolar.cpp
@@ -81,15 +81,6 @@ dp3m_data_struct dp3m;
  */
 static void dp3m_init_a_ai_cao_cut();
 
-/** Calculate for magnetic dipoles the spatial position of the left down mesh
- *  point of the local mesh, to be stored in
- *  @ref p3m_local_mesh::ld_pos "ld_pos".
- *
- *  Function called by @ref dp3m_calc_local_ca_mesh() once and by
- *  @ref dp3m_scaleby_box_l() whenever the box size changes.
- */
-static void dp3m_calc_lm_ld_pos();
-
 /** realloc charge assignment fields. */
 static void dp3m_realloc_ca_fields(int newsize);
 
@@ -98,11 +89,6 @@ static void dp3m_realloc_ca_fields(int newsize);
  */
 static bool dp3m_sanity_checks_boxl();
 
-/** Calculate properties of the local FFT mesh for the
- *   charge assignment process.
- */
-static void dp3m_calc_local_ca_mesh();
-
 /** Interpolate the P-th order charge assignment function from
  *  @cite hockney88a 5-189 (or 8-61). The following charge fractions
  *  are also tabulated in @cite deserno98a @cite deserno98b.
@@ -306,7 +292,7 @@ void dp3m_init() {
       dp3m_realloc_ca_fields(CA_INCREMENT);
     }
 
-    dp3m_calc_local_ca_mesh();
+    p3m_calc_local_ca_mesh(dp3m.local_mesh, dp3m.params, local_geo, skin);
 
     dp3m.sm.resize(comm_cart, dp3m.local_mesh);
 
@@ -1961,17 +1947,6 @@ double dp3m_rtbisection(double box_size, double prefac, double r_cut_iL,
 
 /************************************************************/
 
-void dp3m_calc_lm_ld_pos() {
-  int i;
-  for (i = 0; i < 3; i++) {
-    dp3m.local_mesh.ld_pos[i] =
-        (dp3m.local_mesh.ld_ind[i] + dp3m.params.mesh_off[i]) *
-        dp3m.params.a[i];
-  }
-}
-
-/************************************************************/
-
 void dp3m_init_a_ai_cao_cut() {
   int i;
   for (i = 0; i < 3; i++) {
@@ -1981,90 +1956,6 @@ void dp3m_init_a_ai_cao_cut() {
   }
 }
 
-/************************************************************/
-
-void dp3m_calc_local_ca_mesh() {
-  int i;
-  int ind[3];
-  /* total skin size */
-  double full_skin[3];
-
-  for (i = 0; i < 3; i++)
-    full_skin[i] =
-        dp3m.params.cao_cut[i] + skin + dp3m.params.additional_mesh[i];
-
-  /* inner left down grid point (global index) */
-  for (i = 0; i < 3; i++)
-    dp3m.local_mesh.in_ld[i] = (int)ceil(
-        local_geo.my_left()[i] * dp3m.params.ai[i] - dp3m.params.mesh_off[i]);
-  /* inner up right grid point (global index) */
-  for (i = 0; i < 3; i++)
-    dp3m.local_mesh.in_ur[i] = (int)floor(
-        local_geo.my_right()[i] * dp3m.params.ai[i] - dp3m.params.mesh_off[i]);
-
-  /* correct roundoff errors at boundary */
-  for (i = 0; i < 3; i++) {
-    if ((local_geo.my_right()[i] * dp3m.params.ai[i] -
-         dp3m.params.mesh_off[i]) -
-            dp3m.local_mesh.in_ur[i] <
-        ROUND_ERROR_PREC)
-      dp3m.local_mesh.in_ur[i]--;
-    if (1.0 +
-            (local_geo.my_left()[i] * dp3m.params.ai[i] -
-             dp3m.params.mesh_off[i]) -
-            dp3m.local_mesh.in_ld[i] <
-        ROUND_ERROR_PREC)
-      dp3m.local_mesh.in_ld[i]--;
-  }
-  /* inner grid dimensions */
-  for (i = 0; i < 3; i++)
-    dp3m.local_mesh.inner[i] =
-        dp3m.local_mesh.in_ur[i] - dp3m.local_mesh.in_ld[i] + 1;
-  /* index of left down grid point in global mesh */
-  for (i = 0; i < 3; i++)
-    dp3m.local_mesh.ld_ind[i] =
-        (int)ceil((local_geo.my_left()[i] - full_skin[i]) * dp3m.params.ai[i] -
-                  dp3m.params.mesh_off[i]);
-  /* spacial position of left down mesh point */
-  dp3m_calc_lm_ld_pos();
-  /* left down margin */
-  for (i = 0; i < 3; i++)
-    dp3m.local_mesh.margin[i * 2] =
-        dp3m.local_mesh.in_ld[i] - dp3m.local_mesh.ld_ind[i];
-  /* up right grid point */
-  for (i = 0; i < 3; i++)
-    ind[i] = (int)floor((local_geo.my_right()[i] + full_skin[i]) *
-                            dp3m.params.ai[i] -
-                        dp3m.params.mesh_off[i]);
-  /* correct roundoff errors at up right boundary */
-  for (i = 0; i < 3; i++)
-    if (((local_geo.my_right()[i] + full_skin[i]) * dp3m.params.ai[i] -
-         dp3m.params.mesh_off[i]) -
-            ind[i] ==
-        0)
-      ind[i]--;
-  /* up right margin */
-  for (i = 0; i < 3; i++)
-    dp3m.local_mesh.margin[(i * 2) + 1] = ind[i] - dp3m.local_mesh.in_ur[i];
-
-  /* grid dimension */
-  dp3m.local_mesh.size = 1;
-  for (i = 0; i < 3; i++) {
-    dp3m.local_mesh.dim[i] = ind[i] - dp3m.local_mesh.ld_ind[i] + 1;
-    dp3m.local_mesh.size *= dp3m.local_mesh.dim[i];
-  }
-  /* reduce inner grid indices from global to local */
-  for (i = 0; i < 3; i++)
-    dp3m.local_mesh.in_ld[i] = dp3m.local_mesh.margin[i * 2];
-  for (i = 0; i < 3; i++)
-    dp3m.local_mesh.in_ur[i] =
-        dp3m.local_mesh.margin[i * 2] + dp3m.local_mesh.inner[i];
-
-  dp3m.local_mesh.q_2_off = dp3m.local_mesh.dim[2] - dp3m.params.cao;
-  dp3m.local_mesh.q_21_off =
-      dp3m.local_mesh.dim[2] * (dp3m.local_mesh.dim[1] - dp3m.params.cao);
-}
-
 /*****************************************************************************/
 
 bool dp3m_sanity_checks_boxl() {
@@ -2153,7 +2044,7 @@ void dp3m_scaleby_box_l() {
   dp3m.params.r_cut = dp3m.params.r_cut_iL * box_geo.length()[0];
   dp3m.params.alpha = dp3m.params.alpha_L * (1. / box_geo.length()[0]);
   dp3m_init_a_ai_cao_cut();
-  dp3m_calc_lm_ld_pos();
+  p3m_calc_lm_ld_pos(dp3m.local_mesh, dp3m.params);
   dp3m_sanity_checks_boxl();
 
   dp3m_calc_influence_function_force();
diff --git a/src/core/electrostatics_magnetostatics/p3m.cpp b/src/core/electrostatics_magnetostatics/p3m.cpp
index afec9d01820..f0b90f45443 100644
--- a/src/core/electrostatics_magnetostatics/p3m.cpp
+++ b/src/core/electrostatics_magnetostatics/p3m.cpp
@@ -90,14 +90,6 @@ p3m_data_struct p3m;
  */
 static void p3m_init_a_ai_cao_cut();
 
-/** Calculate the spatial position of the left down mesh point of the local
- *  mesh, to be stored in @ref p3m_local_mesh::ld_pos "ld_pos".
- *
- *  Function called by @ref p3m_calc_local_ca_mesh() once and by
- *  @ref p3m_scaleby_box_l() whenever the box length changes.
- */
-static void p3m_calc_lm_ld_pos();
-
 /** Calculates the dipole term */
 static double p3m_calc_dipole_term(bool force_flag, bool energy_flag,
                                    const ParticleRange &particles);
@@ -114,11 +106,6 @@ static bool p3m_sanity_checks_system(const Utils::Vector3i &grid);
  */
 static bool p3m_sanity_checks_boxl();
 
-/** Calculates properties of the local FFT mesh for the charge assignment
- *  process.
- */
-static void p3m_calc_local_ca_mesh();
-
 /** Interpolate the P-th order charge assignment function from
  *  @cite hockney88a 5-189 (or 8-61). The following charge fractions
  *  are also tabulated in @cite deserno98a @cite deserno98b.
@@ -250,7 +237,7 @@ void p3m_init() {
     p3m_realloc_ca_fields(CA_INCREMENT);
 #endif
 
-    p3m_calc_local_ca_mesh();
+    p3m_calc_local_ca_mesh(p3m.local_mesh, p3m.params, local_geo, skin);
 
     p3m.sm.resize(comm_cart, p3m.local_mesh);
 
@@ -1815,93 +1802,6 @@ void p3m_tune_aliasing_sums(int nx, int ny, int nz, const int mesh[3],
   }
 }
 
-void p3m_calc_local_ca_mesh() {
-  int i;
-  int ind[3];
-  /* total skin size */
-  double full_skin[3];
-
-  for (i = 0; i < 3; i++)
-    full_skin[i] = p3m.params.cao_cut[i] + skin + p3m.params.additional_mesh[i];
-
-  /* inner left down grid point (global index) */
-  for (i = 0; i < 3; i++)
-    p3m.local_mesh.in_ld[i] = (int)ceil(
-        local_geo.my_left()[i] * p3m.params.ai[i] - p3m.params.mesh_off[i]);
-  /* inner up right grid point (global index) */
-  for (i = 0; i < 3; i++)
-    p3m.local_mesh.in_ur[i] = (int)floor(
-        local_geo.my_right()[i] * p3m.params.ai[i] - p3m.params.mesh_off[i]);
-
-  /* correct roundoff errors at boundary */
-  for (i = 0; i < 3; i++) {
-    if ((local_geo.my_right()[i] * p3m.params.ai[i] - p3m.params.mesh_off[i]) -
-            p3m.local_mesh.in_ur[i] <
-        ROUND_ERROR_PREC)
-      p3m.local_mesh.in_ur[i]--;
-    if (1.0 +
-            (local_geo.my_left()[i] * p3m.params.ai[i] -
-             p3m.params.mesh_off[i]) -
-            p3m.local_mesh.in_ld[i] <
-        ROUND_ERROR_PREC)
-      p3m.local_mesh.in_ld[i]--;
-  }
-  /* inner grid dimensions */
-  for (i = 0; i < 3; i++)
-    p3m.local_mesh.inner[i] =
-        p3m.local_mesh.in_ur[i] - p3m.local_mesh.in_ld[i] + 1;
-  /* index of left down grid point in global mesh */
-  for (i = 0; i < 3; i++)
-    p3m.local_mesh.ld_ind[i] =
-        (int)ceil((local_geo.my_left()[i] - full_skin[i]) * p3m.params.ai[i] -
-                  p3m.params.mesh_off[i]);
-  /* left down margin */
-  for (i = 0; i < 3; i++)
-    p3m.local_mesh.margin[i * 2] =
-        p3m.local_mesh.in_ld[i] - p3m.local_mesh.ld_ind[i];
-  /* up right grid point */
-  for (i = 0; i < 3; i++)
-    ind[i] =
-        (int)floor((local_geo.my_right()[i] + full_skin[i]) * p3m.params.ai[i] -
-                   p3m.params.mesh_off[i]);
-  /* correct roundoff errors at up right boundary */
-  for (i = 0; i < 3; i++)
-    if (((local_geo.my_right()[i] + full_skin[i]) * p3m.params.ai[i] -
-         p3m.params.mesh_off[i]) -
-            ind[i] ==
-        0)
-      ind[i]--;
-  /* up right margin */
-  for (i = 0; i < 3; i++)
-    p3m.local_mesh.margin[(i * 2) + 1] = ind[i] - p3m.local_mesh.in_ur[i];
-
-  /* grid dimension */
-  p3m.local_mesh.size = 1;
-  for (i = 0; i < 3; i++) {
-    p3m.local_mesh.dim[i] = ind[i] - p3m.local_mesh.ld_ind[i] + 1;
-    p3m.local_mesh.size *= p3m.local_mesh.dim[i];
-  }
-  /* reduce inner grid indices from global to local */
-  for (i = 0; i < 3; i++)
-    p3m.local_mesh.in_ld[i] = p3m.local_mesh.margin[i * 2];
-  for (i = 0; i < 3; i++)
-    p3m.local_mesh.in_ur[i] =
-        p3m.local_mesh.margin[i * 2] + p3m.local_mesh.inner[i];
-
-  p3m.local_mesh.q_2_off = p3m.local_mesh.dim[2] - p3m.params.cao;
-  p3m.local_mesh.q_21_off =
-      p3m.local_mesh.dim[2] * (p3m.local_mesh.dim[1] - p3m.params.cao);
-}
-
-void p3m_calc_lm_ld_pos() {
-  int i;
-  /* spatial position of left down mesh point */
-  for (i = 0; i < 3; i++) {
-    p3m.local_mesh.ld_pos[i] =
-        (p3m.local_mesh.ld_ind[i] + p3m.params.mesh_off[i]) * p3m.params.a[i];
-  }
-}
-
 void p3m_init_a_ai_cao_cut() {
   int i;
   for (i = 0; i < 3; i++) {
@@ -2002,7 +1902,7 @@ void p3m_scaleby_box_l() {
   p3m.params.r_cut = p3m.params.r_cut_iL * box_geo.length()[0];
   p3m.params.alpha = p3m.params.alpha_L * (1. / box_geo.length()[0]);
   p3m_init_a_ai_cao_cut();
-  p3m_calc_lm_ld_pos();
+  p3m_calc_lm_ld_pos(p3m.local_mesh, p3m.params);
   p3m_sanity_checks_boxl();
   p3m_calc_influence_function_force();
   p3m_calc_influence_function_energy();