diff --git a/src/USER-OMP/pppm_cg_omp.cpp b/src/USER-OMP/pppm_cg_omp.cpp
index 021765d14b..df0e632f78 100644
--- a/src/USER-OMP/pppm_cg_omp.cpp
+++ b/src/USER-OMP/pppm_cg_omp.cpp
@@ -54,6 +54,26 @@ PPPMCGOMP::PPPMCGOMP(LAMMPS *lmp, int narg, char **arg) :
   suffix_flag |= Suffix::OMP;
 }
 
+/* ----------------------------------------------------------------------
+   clean up per-thread allocations
+------------------------------------------------------------------------- */
+
+PPPMCGOMP::~PPPMCGOMP()
+{
+#if defined(_OPENMP)
+#pragma omp parallel default(none)
+#endif
+  {
+#if defined(_OPENMP)
+    const int tid = omp_get_thread_num();
+#else
+    const int tid = 0;
+#endif
+    ThrData *thr = fix->get_thr(tid);
+    thr->init_pppm(-order,memory);
+  }
+}
+
 /* ----------------------------------------------------------------------
    allocate memory that depends on # of K-vectors and order
 ------------------------------------------------------------------------- */
@@ -76,28 +96,6 @@ void PPPMCGOMP::allocate()
   }
 }
 
-/* ----------------------------------------------------------------------
-   free memory that depends on # of K-vectors and order
-------------------------------------------------------------------------- */
-
-void PPPMCGOMP::deallocate()
-{
-  PPPMCG::deallocate();
-
-#if defined(_OPENMP)
-#pragma omp parallel default(none)
-#endif
-  {
-#if defined(_OPENMP)
-    const int tid = omp_get_thread_num();
-#else
-    const int tid = 0;
-#endif
-    ThrData *thr = fix->get_thr(tid);
-    thr->init_pppm(-order,memory);
-  }
-}
-
 /* ----------------------------------------------------------------------
    pre-compute modified (Hockney-Eastwood) Coulomb Green's function
 ------------------------------------------------------------------------- */
diff --git a/src/USER-OMP/pppm_cg_omp.h b/src/USER-OMP/pppm_cg_omp.h
index 91f09ebbfa..07763eba38 100644
--- a/src/USER-OMP/pppm_cg_omp.h
+++ b/src/USER-OMP/pppm_cg_omp.h
@@ -28,12 +28,11 @@ namespace LAMMPS_NS {
 class PPPMCGOMP : public PPPMCG, public ThrOMP {
  public:
   PPPMCGOMP(class LAMMPS *, int, char **);
-  virtual ~PPPMCGOMP () {};
+  virtual ~PPPMCGOMP ();
   virtual void compute(int, int);
 
  protected:
   virtual void allocate();
-  virtual void deallocate();
 
   virtual void compute_gf_ik();
   virtual void compute_gf_ad();
diff --git a/src/USER-OMP/pppm_disp_omp.cpp b/src/USER-OMP/pppm_disp_omp.cpp
index 16d3001ddf..6cf2983761 100644
--- a/src/USER-OMP/pppm_disp_omp.cpp
+++ b/src/USER-OMP/pppm_disp_omp.cpp
@@ -55,7 +55,24 @@ PPPMDispOMP::PPPMDispOMP(LAMMPS *lmp, int narg, char **arg) :
 
 PPPMDispOMP::~PPPMDispOMP()
 {
-  deallocate();
+#if defined(_OPENMP)
+#pragma omp parallel default(none)
+#endif
+  {
+#if defined(_OPENMP)
+    const int tid = omp_get_thread_num();
+#else
+    const int tid = 0;
+#endif
+    if (function[0]) {
+      ThrData * thr = fix->get_thr(tid);
+      thr->init_pppm(-order,memory);
+    }
+    if (function[1] + function[2]) {
+      ThrData * thr = fix->get_thr(tid);
+      thr->init_pppm_disp(-order_6,memory);
+    }
+  }
 }
 
 /* ----------------------------------------------------------------------
@@ -87,34 +104,6 @@ void PPPMDispOMP::allocate()
   }
 }
 
-/* ----------------------------------------------------------------------
-   free memory that depends on # of K-vectors and order
-------------------------------------------------------------------------- */
-
-void PPPMDispOMP::deallocate()
-{
-  PPPMDisp::deallocate();
-
-#if defined(_OPENMP)
-#pragma omp parallel default(none)
-#endif
-  {
-#if defined(_OPENMP)
-    const int tid = omp_get_thread_num();
-#else
-    const int tid = 0;
-#endif
-    if (function[0]) {
-      ThrData * thr = fix->get_thr(tid);
-      thr->init_pppm(-order,memory);
-    }
-    if (function[1] + function[2]) {
-      ThrData * thr = fix->get_thr(tid);
-      thr->init_pppm_disp(-order_6,memory);
-    }
-  }
-}
-
 /* ----------------------------------------------------------------------
    Compute the modified (hockney-eastwood) coulomb green function
 ------------------------------------------------------------------------- */
diff --git a/src/USER-OMP/pppm_disp_omp.h b/src/USER-OMP/pppm_disp_omp.h
index 86c213282a..b1ec2856bb 100644
--- a/src/USER-OMP/pppm_disp_omp.h
+++ b/src/USER-OMP/pppm_disp_omp.h
@@ -33,7 +33,6 @@ namespace LAMMPS_NS {
 
  protected:
   virtual void allocate();
-  virtual void deallocate();
 
   virtual void compute_gf();
   virtual void compute_gf_6();
diff --git a/src/USER-OMP/pppm_disp_tip4p_omp.cpp b/src/USER-OMP/pppm_disp_tip4p_omp.cpp
index 8872c849f3..29aeeb79dc 100644
--- a/src/USER-OMP/pppm_disp_tip4p_omp.cpp
+++ b/src/USER-OMP/pppm_disp_tip4p_omp.cpp
@@ -52,6 +52,31 @@ PPPMDispTIP4POMP::PPPMDispTIP4POMP(LAMMPS *lmp, int narg, char **arg) :
   suffix_flag |= Suffix::OMP;
 }
 
+/* ---------------------------------------------------------------------- */
+
+PPPMDispTIP4POMP::~PPPMDispTIP4POMP()
+{
+
+#if defined(_OPENMP)
+#pragma omp parallel default(none)
+#endif
+  {
+#if defined(_OPENMP)
+    const int tid = omp_get_thread_num();
+#else
+    const int tid = 0;
+#endif
+    if (function[0]) {
+      ThrData * thr = fix->get_thr(tid);
+      thr->init_pppm(-order,memory);
+    }
+    if (function[1] + function[2]) {
+      ThrData * thr = fix->get_thr(tid);
+      thr->init_pppm_disp(-order_6,memory);
+    }
+  }
+}
+
 /* ----------------------------------------------------------------------
    allocate memory that depends on # of K-vectors and order
 ------------------------------------------------------------------------- */
@@ -81,35 +106,6 @@ void PPPMDispTIP4POMP::allocate()
   }
 }
 
-/* ----------------------------------------------------------------------
-   free memory that depends on # of K-vectors and order
-------------------------------------------------------------------------- */
-
-void PPPMDispTIP4POMP::deallocate()
-{
-  PPPMDispTIP4P::deallocate();
-
-#if defined(_OPENMP)
-#pragma omp parallel default(none)
-#endif
-  {
-#if defined(_OPENMP)
-    const int tid = omp_get_thread_num();
-#else
-    const int tid = 0;
-#endif
-    if (function[0]) {
-      ThrData * thr = fix->get_thr(tid);
-      thr->init_pppm(-order,memory);
-    }
-    if (function[1] + function[2]) {
-      ThrData * thr = fix->get_thr(tid);
-      thr->init_pppm_disp(-order_6,memory);
-    }
-  }
-}
-
-
 /* ----------------------------------------------------------------------
    Compute the modified (hockney-eastwood) coulomb green function
 ------------------------------------------------------------------------- */
diff --git a/src/USER-OMP/pppm_disp_tip4p_omp.h b/src/USER-OMP/pppm_disp_tip4p_omp.h
index e05a52ac80..296444366b 100644
--- a/src/USER-OMP/pppm_disp_tip4p_omp.h
+++ b/src/USER-OMP/pppm_disp_tip4p_omp.h
@@ -28,11 +28,10 @@ namespace LAMMPS_NS {
   class PPPMDispTIP4POMP : public PPPMDispTIP4P, public ThrOMP {
  public:
   PPPMDispTIP4POMP(class LAMMPS *, int, char **);
-  virtual ~PPPMDispTIP4POMP () {};
+  virtual ~PPPMDispTIP4POMP ();
 
  protected:
   virtual void allocate();
-  virtual void deallocate();
 
   virtual void compute_gf();
   virtual void compute_gf_6();
diff --git a/src/USER-OMP/pppm_omp.cpp b/src/USER-OMP/pppm_omp.cpp
index a62199be56..48b91e3a7b 100644
--- a/src/USER-OMP/pppm_omp.cpp
+++ b/src/USER-OMP/pppm_omp.cpp
@@ -74,13 +74,11 @@ void PPPMOMP::allocate()
 }
 
 /* ----------------------------------------------------------------------
-   free memory that depends on # of K-vectors and order
+   clean up per-thread allocations
 ------------------------------------------------------------------------- */
 
-void PPPMOMP::deallocate()
+PPPMOMP::~PPPMOMP()
 {
-  PPPM::deallocate();
-
 #if defined(_OPENMP)
 #pragma omp parallel default(none)
 #endif
diff --git a/src/USER-OMP/pppm_omp.h b/src/USER-OMP/pppm_omp.h
index 03eb0e110b..bf8a9e0c21 100644
--- a/src/USER-OMP/pppm_omp.h
+++ b/src/USER-OMP/pppm_omp.h
@@ -28,12 +28,11 @@ namespace LAMMPS_NS {
 class PPPMOMP : public PPPM, public ThrOMP {
  public:
   PPPMOMP(class LAMMPS *, int, char **);
-  virtual ~PPPMOMP () {};
+  virtual ~PPPMOMP ();
   virtual void compute(int, int);
 
  protected:
   virtual void allocate();
-  virtual void deallocate();
 
   virtual void compute_gf_ik();
   virtual void compute_gf_ad();
diff --git a/src/USER-OMP/pppm_tip4p_omp.cpp b/src/USER-OMP/pppm_tip4p_omp.cpp
index 21e3081c65..1eab140cec 100644
--- a/src/USER-OMP/pppm_tip4p_omp.cpp
+++ b/src/USER-OMP/pppm_tip4p_omp.cpp
@@ -52,6 +52,26 @@ PPPMTIP4POMP::PPPMTIP4POMP(LAMMPS *lmp, int narg, char **arg) :
   suffix_flag |= Suffix::OMP;
 }
 
+/* ----------------------------------------------------------------------
+   clean up per-thread allocations
+------------------------------------------------------------------------- */
+
+PPPMTIP4POMP::~PPPMTIP4POMP()
+{
+#if defined(_OPENMP)
+#pragma omp parallel default(none)
+#endif
+  {
+#if defined(_OPENMP)
+    const int tid = omp_get_thread_num();
+#else
+    const int tid = 0;
+#endif
+    ThrData *thr = fix->get_thr(tid);
+    thr->init_pppm(-order,memory);
+  }
+}
+
 /* ----------------------------------------------------------------------
    allocate memory that depends on # of K-vectors and order
 ------------------------------------------------------------------------- */
@@ -74,28 +94,6 @@ void PPPMTIP4POMP::allocate()
   }
 }
 
-/* ----------------------------------------------------------------------
-   free memory that depends on # of K-vectors and order
-------------------------------------------------------------------------- */
-
-void PPPMTIP4POMP::deallocate()
-{
-  PPPMTIP4P::deallocate();
-
-#if defined(_OPENMP)
-#pragma omp parallel default(none)
-#endif
-  {
-#if defined(_OPENMP)
-    const int tid = omp_get_thread_num();
-#else
-    const int tid = 0;
-#endif
-    ThrData *thr = fix->get_thr(tid);
-    thr->init_pppm(-order,memory);
-  }
-}
-
 /* ----------------------------------------------------------------------
    pre-compute modified (Hockney-Eastwood) Coulomb Green's function
 ------------------------------------------------------------------------- */
diff --git a/src/USER-OMP/pppm_tip4p_omp.h b/src/USER-OMP/pppm_tip4p_omp.h
index 0ee807651c..59559cd587 100644
--- a/src/USER-OMP/pppm_tip4p_omp.h
+++ b/src/USER-OMP/pppm_tip4p_omp.h
@@ -28,12 +28,11 @@ namespace LAMMPS_NS {
 class PPPMTIP4POMP : public PPPMTIP4P, public ThrOMP {
  public:
   PPPMTIP4POMP(class LAMMPS *, int, char **);
-  virtual ~PPPMTIP4POMP () {};
+  virtual ~PPPMTIP4POMP ();
   virtual void compute(int, int);
 
  protected:
   virtual void allocate();
-  virtual void deallocate();
 
   virtual void compute_gf_ik();
   virtual void compute_gf_ad();
diff --git a/src/USER-OMP/thr_data.cpp b/src/USER-OMP/thr_data.cpp
index 28fd27f9b8..2ee68fb311 100644
--- a/src/USER-OMP/thr_data.cpp
+++ b/src/USER-OMP/thr_data.cpp
@@ -176,16 +176,22 @@ void ThrData::init_pppm(int order, Memory *memory)
 {
   FFT_SCALAR **rho1d, **drho1d;
   if (order > 0) {
-      memory->create2d_offset(rho1d,3,-order/2,order/2,"thr_data:rho1d");
-      memory->create2d_offset(drho1d,3,-order/2,order/2,"thr_data:drho1d");
-      _rho1d = static_cast<void *>(rho1d);
-      _drho1d = static_cast<void *>(drho1d);
+    rho1d = static_cast<FFT_SCALAR **>(_rho1d);
+    drho1d = static_cast<FFT_SCALAR **>(_drho1d);
+    if (rho1d) memory->destroy2d_offset(rho1d,-order/2);
+    if (drho1d) memory->destroy2d_offset(drho1d,-order/2);
+    memory->create2d_offset(rho1d,3,-order/2,order/2,"thr_data:rho1d");
+    memory->create2d_offset(drho1d,3,-order/2,order/2,"thr_data:drho1d");
+    _rho1d = static_cast<void *>(rho1d);
+    _drho1d = static_cast<void *>(drho1d);
   } else {
     order = -order;
     rho1d = static_cast<FFT_SCALAR **>(_rho1d);
     drho1d = static_cast<FFT_SCALAR **>(_drho1d);
-    memory->destroy2d_offset(rho1d,-order/2);
-    memory->destroy2d_offset(drho1d,-order/2);
+    if (rho1d) memory->destroy2d_offset(rho1d,-order/2);
+    if (drho1d) memory->destroy2d_offset(drho1d,-order/2);
+    _rho1d = NULL;
+    _drho1d = NULL;
   }
 }
 
@@ -203,20 +209,23 @@ void ThrData::init_pppm_disp(int order_6, Memory *memory)
 {
   FFT_SCALAR **rho1d_6, **drho1d_6;
   if (order_6 > 0) {
-      memory->create2d_offset(rho1d_6,3,-order_6/2,order_6/2,"thr_data:rho1d_6");
-      memory->create2d_offset(drho1d_6,3,-order_6/2,order_6/2,"thr_data:drho1d_6");
-      _rho1d_6 = static_cast<void *>(rho1d_6);
-      _drho1d_6 = static_cast<void *>(drho1d_6);
+    rho1d_6 = static_cast<FFT_SCALAR **>(_rho1d_6);
+    drho1d_6 = static_cast<FFT_SCALAR **>(_drho1d_6);
+    if (rho1d_6) memory->destroy2d_offset(rho1d_6,-order_6/2);
+    if (drho1d_6) memory->destroy2d_offset(drho1d_6,-order_6/2);
+    memory->create2d_offset(rho1d_6,3,-order_6/2,order_6/2,"thr_data:rho1d_6");
+    memory->create2d_offset(drho1d_6,3,-order_6/2,order_6/2,"thr_data:drho1d_6");
+    _rho1d_6 = static_cast<void *>(rho1d_6);
+    _drho1d_6 = static_cast<void *>(drho1d_6);
   } else {
     order_6 = -order_6;
     rho1d_6 = static_cast<FFT_SCALAR **>(_rho1d_6);
     drho1d_6 = static_cast<FFT_SCALAR **>(_drho1d_6);
-    memory->destroy2d_offset(rho1d_6,-order_6/2);
-    memory->destroy2d_offset(drho1d_6,-order_6/2);
+    if (rho1d_6) memory->destroy2d_offset(rho1d_6,-order_6/2);
+    if (drho1d_6) memory->destroy2d_offset(drho1d_6,-order_6/2);
   }
 }
 
-
 /* ----------------------------------------------------------------------
    compute global pair virial via summing F dot r over own & ghost atoms
    at this point, only pairwise forces have been accumulated in atom->f