diff --git a/src/bst_helpers.jl b/src/bst_helpers.jl
index 5115be0..8472b42 100644
--- a/src/bst_helpers.jl
+++ b/src/bst_helpers.jl
@@ -3,9 +3,8 @@
 """
     function bst_single_excitonic_basis(clusters, fspace::FockConfig{N}; R=1, Nk=2, T=Float64) where {N}
 """
-function bst_single_excitonic_basis(clusters, fspace::FockConfig{N}, cluster_bases::Vector{ClusterBasis{A, T}}; R=1,number_of_single_excitations=4) where {N, T, A}
+function bst_single_excitonic_basis(fspace::FockConfig{N}, ci_vector::BSTstate{T,N,A}; R=1,number_of_single_excitations=4) where {N, T, A}
     max_index = length(fspace.config)
-    ci_vector = BSTstate(clusters, fspace, cluster_bases, R=R)
     dims = ones(Int, max_index)
     configs = []
     for i in 2:number_of_single_excitations
@@ -15,7 +14,7 @@ function bst_single_excitonic_basis(clusters, fspace::FockConfig{N}, cluster_bas
         end
     end
     for config in configs
-        ci_vector[FermiCG.FockConfig(init_fspace)][FermiCG.TuckerConfig(config)] =
+        ci_vector[fspace][FermiCG.TuckerConfig(config)] =
             FermiCG.Tucker(tuple([zeros(Float64, dims...) for _ in 1:R]...))
     end
     return ci_vector
@@ -23,9 +22,8 @@ end
 """
         function bst_biexcitonic_basis(clusters, fspace::FockConfig{N}; R=1, Nk=2, T=Float64) where {N}
 """
-function bst_biexcitonic_basis(clusters, fspace::FockConfig{N}, cluster_bases::Vector{ClusterBasis{A, T}}; R=1) where {N, T, A}
+function bst_biexcitonic_basis(fspace::FockConfig{N},ci_vector::BSTstate{T,N,A}; R=1) where {N, T, A}
     max_index = length(fspace.config)
-    ci_vector = BSTstate(clusters, fspace, cluster_bases, R=R)
     configs = []
     for indices in combinations(1:max_index, 2)
         config = [in(k, indices) ? (2:2) : (1:1) for k in 1:max_index]
@@ -33,7 +31,7 @@ function bst_biexcitonic_basis(clusters, fspace::FockConfig{N}, cluster_bases::V
     end
     dims = ones(Int, max_index)
     for config in configs
-        ci_vector[FermiCG.FockConfig(init_fspace)][FermiCG.TuckerConfig(config)] =
+        ci_vector[fspace][FermiCG.TuckerConfig(config)] =
             FermiCG.Tucker(tuple([zeros(Float64, dims...) for _ in 1:R]...))
     end