diff --git a/org/qmckl_electron.org b/org/qmckl_electron.org
index 8bc9f4b..621235d 100644
--- a/org/qmckl_electron.org
+++ b/org/qmckl_electron.org
@@ -1199,7 +1199,7 @@ qmckl_get_electron_en_distance(qmckl_context context,
                            "distance is a null pointer");
   }
 
-  size_t sze = ctx->point.num * ctx->nucleus.num;
+  int64_t sze = ctx->point.num * ctx->nucleus.num;
   if (size_max < sze) {
     return qmckl_failwith( context,
                            QMCKL_INVALID_ARG_3,
diff --git a/org/qmckl_jastrow_champ_single.org b/org/qmckl_jastrow_champ_single.org
index 4e1d520..4dafa92 100644
--- a/org/qmckl_jastrow_champ_single.org
+++ b/org/qmckl_jastrow_champ_single.org
@@ -112,8 +112,10 @@ typedef struct qmckl_jastrow_champ_single_struct{
   double  *    restrict een_rescaled_single_n_gl;
   uint64_t     een_rescaled_single_n_gl_date;
   double*      delta_p_gl;
+  uint64_t     delta_p_gl_maxsize;
   uint64_t     delta_p_gl_date;
   double*      delta_een_gl;
+  uint64_t     delta_een_gl_maxsize;
   uint64_t     delta_een_gl_date;
   double*      delta_een_g;
   uint64_t     delta_een_g_date;
@@ -3156,7 +3158,11 @@ qmckl_exit_code qmckl_provide_jastrow_champ_delta_p_gl(qmckl_context context)
   /* Compute if necessary */
   if (ctx->single_point.date > ctx->single_point.delta_p_gl_date) {
 
-    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
+    qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
+    mem_info.size = 4 * ctx->electron.walker.num * ctx->jastrow_champ.cord_num *
+                  (ctx->jastrow_champ.cord_num + 1) * ctx->nucleus.num *  ctx->electron.num * sizeof(double);
+
+    if (mem_info.size > ctx->single_point.delta_p_gl_maxsize) {
       if (ctx->single_point.delta_p_gl != NULL) {
         rc = qmckl_free(context, ctx->single_point.delta_p_gl);
         if (rc != QMCKL_SUCCESS) {
@@ -3171,10 +3177,8 @@ qmckl_exit_code qmckl_provide_jastrow_champ_delta_p_gl(qmckl_context context)
     /* Allocate array */
     if (ctx->single_point.delta_p_gl == NULL) {
 
-      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
-      mem_info.size = 4 * ctx->electron.walker.num * ctx->jastrow_champ.cord_num *
-                  (ctx->jastrow_champ.cord_num + 1) * ctx->nucleus.num *  ctx->electron.num * sizeof(double);
       double* delta_p_gl = (double*) qmckl_malloc(context, mem_info);
+      ctx->single_point.delta_p_gl_maxsize = mem_info.size;
 
       if (delta_p_gl == NULL) {
         return qmckl_failwith( context,
@@ -3551,7 +3555,10 @@ qmckl_exit_code qmckl_provide_jastrow_champ_single_een_gl(qmckl_context context)
   /* Compute if necessary */
   if (ctx->single_point.date > ctx->single_point.delta_een_gl_date) {
 
-    if (ctx->electron.walker.num > ctx->electron.walker_old.num) {
+    qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
+    mem_info.size = 4 * ctx->electron.num * ctx->electron.walker.num * sizeof(double);
+
+    if (mem_info.size > ctx->single_point.delta_een_gl_maxsize) {
       if (ctx->single_point.delta_een_gl != NULL) {
         rc = qmckl_free(context, ctx->single_point.delta_een_gl);
         if (rc != QMCKL_SUCCESS) {
@@ -3566,9 +3573,8 @@ qmckl_exit_code qmckl_provide_jastrow_champ_single_een_gl(qmckl_context context)
     /* Allocate array */
     if (ctx->single_point.delta_een_gl == NULL) {
 
-      qmckl_memory_info_struct mem_info = qmckl_memory_info_struct_zero;
-      mem_info.size = 4 * ctx->electron.num * ctx->electron.walker.num * sizeof(double);
       double* delta_een_gl = (double*) qmckl_malloc(context, mem_info);
+      ctx->single_point.delta_een_gl_maxsize = mem_info.size;
 
       if (delta_een_gl == NULL) {
         return qmckl_failwith( context,