diff --git a/src/bases.jl b/src/bases.jl
index dfc9faf..1755464 100644
--- a/src/bases.jl
+++ b/src/bases.jl
@@ -1,3 +1,3 @@
-import QuantumInterface: Basis, basis, GenericBasis, CompositeBasis,
+import QuantumInterface: Basis, basis, GenericBasis, CompositeBasis, ParticleBasis, PositionBasis, MomentumBasis,
     equal_shape, equal_bases, IncompatibleBases, @samebases, samebases, check_samebases,
     multiplicable, check_multiplicable, reduced, ptrace, permutesystems
diff --git a/src/particle.jl b/src/particle.jl
index e0f5ff8..5aafde0 100644
--- a/src/particle.jl
+++ b/src/particle.jl
@@ -1,74 +1,6 @@
 import Base: position # TODO is it a good idea to abuse the Base namespace for a different use?
 using FFTW
 
-abstract type ParticleBasis <: Basis end
-
-"""
-    PositionBasis(xmin, xmax, Npoints)
-    PositionBasis(b::MomentumBasis)
-
-Basis for a particle in real space.
-
-For simplicity periodic boundaries are assumed which means that
-the rightmost point defined by `xmax` is not included in the basis
-but is defined to be the same as `xmin`.
-
-When a [`MomentumBasis`](@ref) is given as argument the exact values
-of ``x_{min}`` and ``x_{max}`` are due to the periodic boundary conditions
-more or less arbitrary and are chosen to be
-``-\\pi/dp`` and ``\\pi/dp`` with ``dp=(p_{max}-p_{min})/N``.
-"""
-struct PositionBasis{X1,X2,T,F} <: ParticleBasis
-    shape::Vector{T}
-    xmin::F
-    xmax::F
-    N::T
-    function PositionBasis{X1,X2}(xmin::F, xmax::F, N::T) where {X1,X2,F,T<:Integer}
-        @assert isa(X1, Real) && isa(X2, Real)
-        new{X1,X2,T,F}([N], xmin, xmax, N)
-    end
-end
-function PositionBasis(xmin::F1, xmax::F2, N) where {F1,F2}
-    F = promote_type(F1,F2)
-    return PositionBasis{xmin,xmax}(convert(F,xmin),convert(F,xmax),N)
-end
-
-"""
-    MomentumBasis(pmin, pmax, Npoints)
-    MomentumBasis(b::PositionBasis)
-
-Basis for a particle in momentum space.
-
-For simplicity periodic boundaries are assumed which means that
-`pmax` is not included in the basis but is defined to be the same as `pmin`.
-
-When a [`PositionBasis`](@ref) is given as argument the exact values
-of ``p_{min}`` and ``p_{max}`` are due to the periodic boundary conditions
-more or less arbitrary and are chosen to be
-``-\\pi/dx`` and ``\\pi/dx`` with ``dx=(x_{max}-x_{min})/N``.
-"""
-struct MomentumBasis{P1,P2,T,F} <: ParticleBasis
-    shape::Vector{T}
-    pmin::F
-    pmax::F
-    N::T
-    function MomentumBasis{P1,P2}(pmin::F, pmax::F, N::T) where {T<:Integer,F,P1,P2}
-        @assert isa(P1, Real) && isa(P2, Real)
-        new{P1,P2,T,F}([N], pmin, pmax, N)
-    end
-end
-function MomentumBasis(pmin::F1, pmax::F2, N) where {F1,F2}
-    F = promote_type(F1,F2)
-    return MomentumBasis{pmin,pmax}(convert(F,pmin), convert(F,pmax), N)
-end
-
-PositionBasis(b::MomentumBasis) = (dp = (b.pmax - b.pmin)/b.N; PositionBasis(-pi/dp, pi/dp, b.N))
-MomentumBasis(b::PositionBasis) = (dx = (b.xmax - b.xmin)/b.N; MomentumBasis(-pi/dx, pi/dx, b.N))
-
-==(b1::PositionBasis, b2::PositionBasis) = b1.xmin==b2.xmin && b1.xmax==b2.xmax && b1.N==b2.N
-==(b1::MomentumBasis, b2::MomentumBasis) = b1.pmin==b2.pmin && b1.pmax==b2.pmax && b1.N==b2.N
-
-
 """
     gaussianstate([T=ComplexF64,] b::PositionBasis, x0, p0, sigma)
     gaussianstate([T=ComplexF64,] b::MomentumBasis, x0, p0, sigma)
diff --git a/src/printing.jl b/src/printing.jl
index f4aec6b..929456e 100644
--- a/src/printing.jl
+++ b/src/printing.jl
@@ -20,14 +20,6 @@ end
 set_printing(standard_order=false, rounding_tol=1e-17)
 
 
-function show(stream::IO, x::PositionBasis)
-    write(stream, "Position(xmin=$(x.xmin), xmax=$(x.xmax), N=$(x.N))")
-end
-
-function show(stream::IO, x::MomentumBasis)
-    write(stream, "Momentum(pmin=$(x.pmin), pmax=$(x.pmax), N=$(x.N))")
-end
-
 function show(stream::IO, x::SubspaceBasis)
     write(stream, "Subspace(superbasis=$(x.superbasis), states:$(length(x.basisstates)))")
 end