diff --git a/qpms/qpms_c.pyx b/qpms/qpms_c.pyx
index 0ebc072..e421e31 100644
--- a/qpms/qpms_c.pyx
+++ b/qpms/qpms_c.pyx
@@ -422,8 +422,8 @@ cdef class ScatteringSystem:
                 orig.p[pi].pos = p.cval().pos
                 orig.p[pi].tmatrix_id = tmindices[tm_derived_key]
             ssw = qpms_scatsys_apply_symmetry(&orig, sym.rawpointer(), omega, &QPMS_TOLERANCE_DEFAULT)
-            qpms_ss_create_translation_cache(ss, caching_mode)
             ss = ssw[0].ss
+            qpms_ss_create_translation_cache(ss, caching_mode)
         finally:
             free(orig.tmg)
             free(orig.tm)
@@ -606,6 +606,11 @@ cdef class ScatteringSystem:
                 self.s, qpms_incfield_planewave, <void *>&p, 0)
         return target_np
 
+    property has_translation_cache:
+        def __get__(self):
+            self.check_s()
+            return True if qpms_scatsys_has_translation_cache(self.s) else False
+
     def find_modes(self, cdouble omega_centre, double omega_rr, double omega_ri, iri = None,
             size_t contour_points = 20, double rank_tol = 1e-4, size_t rank_min_sel=1,
             double res_tol = 0):
@@ -633,6 +638,8 @@ cdef class ScatteringSystem:
         cdef np.ndarray[double, ndim=1] ranktest_SV = np.empty((vlen), dtype=np.double)
         cdef double[::1] ranktest_SV_v = ranktest_SV
 
+        cdef size_t i, j
+
         for i in range(neig):
             eigval_v[i] = res[0].eigval[i]
             eigval_err_v[i] = res[0].eigval_err[i]
@@ -705,6 +712,10 @@ cdef class _ScatteringSystemAtOmega:
         def __get__(self): return self.ss_pyref.irrep_names
     property nirreps: 
         def __get__(self): return self.ss_pyref.nirreps
+    property has_translation_cache:
+        def __get__(self):
+            self.check()
+            return True if qpms_scatsysw_has_translation_cache(self.ssw) else False
 
     def add_translation_cache(self):
         '''
@@ -715,6 +726,7 @@ cdef class _ScatteringSystemAtOmega:
         '''
         self.check()
         qpms_ssw_create_translation_cache(self.ssw)
+        return self.has_translation_cache
 
     def modeproblem_matrix_full(self):
         self.check()
diff --git a/qpms/qpms_cdefs.pxd b/qpms/qpms_cdefs.pxd
index ba6477e..08c853c 100644
--- a/qpms/qpms_cdefs.pxd
+++ b/qpms/qpms_cdefs.pxd
@@ -609,6 +609,8 @@ cdef extern from "scatsystem.h":
     beyn_result_t *qpms_scatsys_finite_find_eigenmodes(const qpms_scatsys_t *ss, qpms_iri_t iri,
             cdouble omega_centre, double omega_rr, double omega_ri, size_t contour_npoints, 
             double rank_tol, size_t rank_sel_min, double res_tol)
+    bint qpms_scatsysw_has_translation_cache(const qpms_scatsys_at_omega_t *ssw)
+    bint qpms_scatsys_has_translation_cache(const qpms_scatsys_t *ss)
 
 cdef extern from "ewald.h":
     struct qpms_csf_result:
diff --git a/qpms/scatsystem.c b/qpms/scatsystem.c
index 38b88b6..dfc42c1 100644
--- a/qpms/scatsystem.c
+++ b/qpms/scatsystem.c
@@ -210,6 +210,7 @@ qpms_scatsys_at_omega_t *qpms_scatsys_apply_symmetry(const qpms_scatsys_t *orig,
   QPMS_CRASHING_MALLOC(ssw, sizeof(*ssw)); // returned
   ssw->ss = ss;
   ssw->omega = omega;
+  ssw->translation_cache = NULL;
   ssw->medium = qpms_epsmu_generator_eval(ss->medium, omega);
   ssw->wavenumber = qpms_wavenumber(omega, ssw->medium);
   // we will be using ss->tm_capacity also for ssw->tm
diff --git a/qpms/scatsystem.h b/qpms/scatsystem.h
index 79fdf0d..3252418 100644
--- a/qpms/scatsystem.h
+++ b/qpms/scatsystem.h
@@ -193,6 +193,11 @@ typedef struct qpms_scatsys_t {
 
 } qpms_scatsys_t;
 
+/// Returns true if ss has the translation caching metadata populated.
+static inline _Bool qpms_scatsys_has_translation_cache(const qpms_scatsys_t *ss) {
+	return ss->tbooster != NULL;
+}
+
 /// Retrieve the bspec of \a tmi'th element of \a ss->tm.
 static inline const qpms_vswf_set_spec_t *qpms_ss_bspec_tmi(const qpms_scatsys_t *ss, qpms_ss_tmi_t tmi) {
 	return ss->tmg[ss->tm[tmi].tmgi].spec;
@@ -217,7 +222,7 @@ typedef struct qpms_scatsys_at_omega_t {
 	qpms_epsmu_t medium; ///< Background medium optical properties at the given frequency
 	complex double wavenumber; ///< Background medium wavenumber
 
-	struct qpms_scatsysw_translation_booster *translation_cache; ///< (private) cache to speedup tranlations
+	struct qpms_scatsysw_translation_booster *translation_cache; ///< (private) cache to speedup translations
 } qpms_scatsys_at_omega_t;
 
 
@@ -283,6 +288,11 @@ typedef enum qpms_ss_caching_mode {
 	QPMS_SS_CACHE_DEFAULT = QPMS_SS_CACHE_AUTO
 } qpms_ss_caching_mode_t;
 
+/// Returns true if ssw has the translation operator cache populated.
+static inline _Bool qpms_scatsysw_has_translation_cache(const qpms_scatsys_at_omega_t *ssw) {
+	return ssw->translation_cache != NULL;
+}
+
 /// Creates some data structures for speeding up translation operator calculations.
 /** This is mostly useful for "finite lattices", where many pairs of nanoparticles
  * share the same relative positions.