diff --git a/src/include/clu_subs.h b/src/include/clu_subs.h
index a02d51b70bd51aecd373c08183ee929b54b8ab5c..fa30ee95065a7db6f98f103d507479c82e47de8c 100644
--- a/src/include/clu_subs.h
+++ b/src/include/clu_subs.h
@@ -90,7 +90,13 @@ dcomplex cdtp(dcomplex z, dcomplex **am, int i, int jf, int k, int nj);
  * \param m: `int`
  * \return result: `double`
  */
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp begin declare target device_type(any)
+#endif
 double cgev(int ipamo, int mu, int l, int m);
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp end declare target
+#endif
 
 /*! \brief Build the multi-centered M-matrix of the cluster.
  *
@@ -129,10 +135,16 @@ void crsm1(double vk, double exri, ParticleDescriptor *c1);
  * \param c1: `ParticleDescriptor *`
  * \param rac3j: `dcomplex *`
  */
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp begin declare target device_type(any)
+#endif
 dcomplex ghit_d(
 	      int ihi, int ipamo, int nbl, int l1, int m1, int l2, int m2,
 	      ParticleDescriptor *c1, double *rac3j
 );
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp end declare target
+#endif
 
 /*! \brief Compute the transfer vector from N2 to N1.
  *
@@ -148,10 +160,16 @@ dcomplex ghit_d(
  * \param m2: `int`
  * \param c1: `ParticleDescriptor *` Poiunter to a ParticleDescriptor instance.
  */
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp begin declare target device_type(any)
+#endif
 dcomplex ghit(
 	      int ihi, int ipamo, int nbl, int l1, int m1, int l2, int m2,
 	      ParticleDescriptor *c1
 );
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp end declare target
+#endif
 
 /*! \brief Compute Hankel funtion and Bessel functions.
  *
@@ -261,7 +279,13 @@ void r3j000(int j2, int j3, double *rac3j);
  * \param m3: `int`
  * \param rac3j: `double *` Vector of 3j symbols.
  */
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp begin declare target device_type(any)
+#endif
 void r3jjr(int j2, int j3, int m2, int m3, double *rac3j);
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp end declare target
+#endif
 
 /*! \brief Compute the 3j symbol for Clebsch-Gordan coefficients for JJ transitions.
  *
@@ -274,7 +298,13 @@ void r3jjr(int j2, int j3, int m2, int m3, double *rac3j);
  * \param m3: `int`
  * \param rac3j: `double *`
  */
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp begin declare target device_type(any)
+#endif
 void r3jjr_d(int j2, int j3, int m2, int m3, double *rac3j);
+#ifdef USE_TARGET_OFFLOAD
+#pragma omp end declare target
+#endif
 
 /*! \brief Compute the 3j symbol for Clebsch-Gordan coefficients for JM transitions.
  *