diff --git a/fftma_module/gen/lib_src/fftma2.c b/fftma_module/gen/lib_src/fftma2.c
index 5cfcb6f..3df9e3a 100644
--- a/fftma_module/gen/lib_src/fftma2.c
+++ b/fftma_module/gen/lib_src/fftma2.c
@@ -53,8 +53,6 @@ void FFTMA2(struct vario_mod variogram, struct grid_mod grid, int n[3], struct r
 
     /*array initialization*/
     covar = chunk_array_create("covar.txt", ntot);
-    ireal = chunk_array_create("ireal.txt", ntot);
-    realization = chunk_array_create("realization.txt", ntot);
 
     workr = (double*)malloc(nmax * sizeof(double));
     testmemory(workr);
@@ -69,9 +67,13 @@ void FFTMA2(struct vario_mod variogram, struct grid_mod grid, int n[3], struct r
 
     printf("termine covariance\n");
 
+    ireal = chunk_array_create("ireal.txt", ntot);
+
     /*power spectrum*/
     fourt(covar, ireal, n, NDIM, 1, 0, workr, worki);
 
+    realization = chunk_array_create("realization.txt", ntot);
+
     /*organization of the input Gaussian white noise*/
     solver = 0;
     prebuild_gwn(grid, n, realin, realization, solver, seed);