diff --git a/mala/common/parameters.py b/mala/common/parameters.py
index 64325a77b..c1829b6d2 100644
--- a/mala/common/parameters.py
+++ b/mala/common/parameters.py
@@ -382,8 +382,14 @@ def __init__(self):
         self.ace_M_R = 0
 
         self.ace_coupling_type = "cg"
-
         self.ace_lmax_traditional = 12
+        
+        # TODO: add consistency check for these
+        # if grid_filter, types_like_snap must be False
+        # if grid_filter, padfunc must be True
+        self.ace_grid_filter = True
+        self.ace_types_like_snap = False
+        self.ace_padfunc = True
 
 
     @property
diff --git a/mala/descriptors/ace.py b/mala/descriptors/ace.py
index 8b8b6adc8..d6f9ec8b0 100755
--- a/mala/descriptors/ace.py
+++ b/mala/descriptors/ace.py
@@ -520,6 +520,9 @@ def calculate_coupling_coeffs(self):
                 + " not recongised"
             )
 
+        limit_nus = self.calc_limit_nus()
+
+    def calc_limit_nus(self):
         ranked_chem_nus = []
         for ind, rank in enumerate(self.parameters.ace_ranks):
             rank = int(rank)
@@ -532,6 +535,66 @@ def calculate_coupling_coeffs(self):
             )
             ranked_chem_nus.append(PA_lammps)
 
+        nus_unsort = [item for sublist in ranked_chem_nus for item in sublist]
+        nus = nus_unsort.copy()
+        mu0s = []
+        mus = []
+        ns = []
+        ls = []
+        for nu in nus_unsort:
+            mu0ii, muii, nii, lii = acu.get_mu_n_l(nu)
+            mu0s.append(mu0ii)
+            mus.append(tuple(muii))
+            ns.append(tuple(nii))
+            ls.append(tuple(lii))
+        nus.sort(key=lambda x: mus[nus_unsort.index(x)], reverse=False)
+        nus.sort(key=lambda x: ns[nus_unsort.index(x)], reverse=False)
+        nus.sort(key=lambda x: ls[nus_unsort.index(x)], reverse=False)
+        nus.sort(key=lambda x: mu0s[nus_unsort.index(x)], reverse=False)
+        nus.sort(key=lambda x: len(x), reverse=False)
+        nus.sort(key=lambda x: mu0s[nus_unsort.index(x)], reverse=False)
+        musins = range(len(self.parameters.ace_elements) - 1)
+        all_funcs = {}
+        if self.parameters.ace_types_like_snap:
+            byattyp, byattypfiltered = self.srt_by_attyp(nus, 1)
+            if self.parameters.ace_grid_filter:
+                assert (
+                    self.parameters.ace_padfunc
+                ), "must pad with at least 1 other basis function for other element types to work in LAMMPS - set padfunc=True"
+                limit_nus = byattypfiltered["%d" % 0]
+                if self.parameters.ace_padfunc:
+                    for muii in musins:
+                        limit_nus.append(byattypfiltered["%d" % muii][0])
+            elif not grid_filter:
+                limit_nus = byattyp["%d" % 0]
+
+        else:
+            byattyp, byattypfiltered = self.srt_by_attyp(
+                nus, len(self.parameters.ace_elements)
+            )
+            if self.parameters.ace_grid_filter:
+                limit_nus = byattypfiltered[
+                    "%d" % (len(self.parameters.ace_elements) - 1)
+                ]
+                assert (
+                    self.parameters.ace_padfunc
+                ), "must pad with at least 1 other basis function for other element types to work in LAMMPS - set padfunc=True"
+                if self.parameters.ace_padfunc:
+                    for muii in musins:
+                        limit_nus.append(byattypfiltered["%d" % muii][0])
+            elif not grid_filter:
+                limit_nus = byattyp[
+                    "%d" % (len(self.parameters.ace_elements) - 1)
+                ]
+                if self.parameters.ace_padfunc:
+                    for muii in musins:
+                        limit_nus.append(byattyp["%d" % muii][0])
+        printout(
+            "all basis functions", len(nus), "grid subset", len(limit_nus)
+        )
+
+        return limit_nus
+
     def get_default_settings(self):
         rc_range = {bp: None for bp in self.bonds}
         rin_def = {bp: None for bp in self.bonds}
@@ -653,7 +716,7 @@ def srt_by_attyp(self, nulst, remove_type=2):
         for nu in nulst:
             mu0 = nu.split("_")[0]
             byattyp[mu0].append(nu)
-            mu0ii, muii, nii, lii = get_mu_n_l(nu)
+            mu0ii, muii, nii, lii = acu.get_mu_n_l(nu)
             if mumax not in muii:
                 byattypfiltered[mu0].append(nu)
         return byattyp, byattypfiltered
diff --git a/mala/descriptors/ace_coupling_utils.py b/mala/descriptors/ace_coupling_utils.py
index 573a18bdd..9bee88529 100644
--- a/mala/descriptors/ace_coupling_utils.py
+++ b/mala/descriptors/ace_coupling_utils.py
@@ -543,3 +543,50 @@ def ind_vec(lrng, size):
             if pstr not in uniques:
                 uniques.append(pstr)
     return uniques
+
+
+def get_mu_n_l(nu_in, return_L=False, **kwargs):
+    rank = get_mu_nu_rank(nu_in)
+    if len(nu_in.split("_")) > 1:
+        if len(nu_in.split("_")) == 2:
+            nu = nu_in.split("_")[-1]
+            Lstr = ""
+        else:
+            nu = nu_in.split("_")[1]
+            Lstr = nu_in.split("_")[-1]
+        mu0 = int(nu_in.split("_")[0])
+        nusplt = [int(k) for k in nu.split(",")]
+        mu = nusplt[:rank]
+        n = nusplt[rank : 2 * rank]
+        l = nusplt[2 * rank :]
+        if len(Lstr) >= 1:
+            L = tuple([int(k) for k in Lstr.split("-")])
+        else:
+            L = None
+        if return_L:
+            return mu0, mu, n, l, L
+        else:
+            return mu0, mu, n, l
+    # provide option to get n,l for depricated descriptor labels
+    else:
+        nu = nu_in
+        mu0 = 0
+        mu = [0] * rank
+        nusplt = [int(k) for k in nu.split(",")]
+        n = nusplt[:rank]
+        l = nusplt[rank : 2 * rank]
+        return mu0, mu, n, l
+
+
+def get_mu_nu_rank(nu_in):
+    if len(nu_in.split("_")) > 1:
+        assert (
+            len(nu_in.split("_")) <= 3
+        ), "make sure your descriptor label is in proper format: mu0_mu1,mu2,mu3,n1,n2,n3,l1,l2,l3_L1"
+        nu = nu_in.split("_")[1]
+        nu_splt = nu.split(",")
+        return int(len(nu_splt) / 3)
+    else:
+        nu = nu_in
+        nu_splt = nu.split(",")
+        return int(len(nu_splt) / 2)