diff --git a/src/KSPACE/pppm.cpp b/src/KSPACE/pppm.cpp
index 174b00f3b7..b8891bf4de 100644
--- a/src/KSPACE/pppm.cpp
+++ b/src/KSPACE/pppm.cpp
@@ -780,14 +780,13 @@ void PPPM::set_grid()
   // reduce it until accuracy target is met
 
   if (!gridflag) {
-
     if (differentiation_flag == 1) {
-
       h = h_x = h_y = h_z = 4.0/g_ewald;
       int count = 0;
       while (1) {
 
         // set grid dimension
+
         nx_pppm = static_cast<int> (xprd/h_x);
         ny_pppm = static_cast<int> (yprd/h_y);
         nz_pppm = static_cast<int> (zprd_slab/h_z);
@@ -796,7 +795,8 @@ void PPPM::set_grid()
         if (ny_pppm <= 1) ny_pppm = 2;
         if (nz_pppm <= 1) nz_pppm = 2;
 
-        //set local grid dimension
+        // set local grid dimension
+
         int npey_fft,npez_fft;
         if (nz_pppm >= nprocs) {
           npey_fft = 1;
@@ -814,20 +814,18 @@ void PPPM::set_grid()
         nzhi_fft = (me_z+1)*nz_pppm/npez_fft - 1;
 
         double df_kspace = compute_df_kspace();
-
         count++;
 
         // break loop if the accuracy has been reached or
-        // too many loops have been performed
+        // if too many loops have been performed
 
         if (df_kspace <= accuracy) break;
-        if (count > 500) error->all(FLERR, "Could not compute grid size!");
+        if (count > 500) error->all(FLERR,"Could not compute PPPM grid size");
         h *= 0.95;
         h_x = h_y = h_z = h;
       }
 
     } else {
-
       double err;
       h_x = h_y = h_z = 1.0/g_ewald;
 
@@ -1000,6 +998,7 @@ double PPPM::compute_qopt()
       }
     }
   }
+
   double qopt_all;
   MPI_Allreduce(&qopt,&qopt_all,1,MPI_DOUBLE,MPI_SUM,world);
   return qopt_all;
@@ -1053,9 +1052,7 @@ double PPPM::newton_raphson_f()
 
   double df_rspace = 2.0*q2*exp(-g_ewald*g_ewald*cutoff*cutoff) /
        sqrt(natoms*cutoff*xprd*yprd*zprd);
-
   double df_kspace = compute_df_kspace();
-
   return df_rspace - df_kspace;
 }
 
diff --git a/src/KSPACE/pppm.h b/src/KSPACE/pppm.h
index f5b07a03f3..36ac99a405 100644
--- a/src/KSPACE/pppm.h
+++ b/src/KSPACE/pppm.h
@@ -81,7 +81,8 @@ class PPPM : public KSpace {
 
   double *gf_b;
   FFT_SCALAR **rho1d,**rho_coeff,**drho1d,**drho_coeff;
-  double *sf_precoeff1, *sf_precoeff2, *sf_precoeff3, *sf_precoeff4, *sf_precoeff5, *sf_precoeff6;
+  double *sf_precoeff1, *sf_precoeff2, *sf_precoeff3;
+  double *sf_precoeff4, *sf_precoeff5, *sf_precoeff6;
   double sf_coeff[6];          // coefficients for calculating ad self-forces
   double **acons;
 
diff --git a/src/kspace.h b/src/kspace.h
index 2d6d8f6486..1110269a6f 100644
--- a/src/kspace.h
+++ b/src/kspace.h
@@ -45,8 +45,8 @@ class KSpace : protected Pointers {
   int proxyflag;                 // 1 if a proxy solver
 
   double g_ewald,g_ewald_6;
-  int nx_pppm,ny_pppm,nz_pppm;
-  int nx_pppm_6,ny_pppm_6,nz_pppm_6;
+  int nx_pppm,ny_pppm,nz_pppm;           // global FFT grid for Coulombics
+  int nx_pppm_6,ny_pppm_6,nz_pppm_6;     // global FFT grid for dispersion
   int nx_msm_max,ny_msm_max,nz_msm_max;
 
   int group_group_enable;         // 1 if style supports group/group calculation
@@ -69,14 +69,10 @@ class KSpace : protected Pointers {
   virtual void compute(int, int) = 0;
   virtual void compute_group_group(int, int, int) {};
 
-  virtual int pack_forward(int, FFT_SCALAR *,
-                           int, int, int, int, int, int) {return 0;};
-  virtual void unpack_forward(int, FFT_SCALAR *,
-                              int, int, int, int, int, int) {};
-  virtual int pack_reverse(int, FFT_SCALAR *,
-                           int, int, int, int, int, int) {return 0;};
-  virtual void unpack_reverse(int, FFT_SCALAR *,
-                              int, int, int, int, int, int) {};
+  virtual int pack_forward(int, FFT_SCALAR *, int, int *) {return 0;};
+  virtual void unpack_forward(int, FFT_SCALAR *, int, int *) {};
+  virtual int pack_reverse(int, FFT_SCALAR *, int, int *) {return 0;};
+  virtual void unpack_reverse(int, FFT_SCALAR *, int, int *) {};
 
   virtual int timing(int, double &, double &) {return 0;}
   virtual int timing_1d(int, double &) {return 0;}