diff --git a/Project.toml b/Project.toml
index e1d14c98eb..d18021aada 100644
--- a/Project.toml
+++ b/Project.toml
@@ -72,8 +72,8 @@ DFTKWriteVTKExt = "WriteVTK"
 [compat]
 AbstractFFTs = "1"
 Artifacts = "1"
-AtomsBase = "0.3.1"
-AtomsCalculators = "0.1"
+AtomsBase = "0.4"
+AtomsCalculators = "0.2"
 Brillouin = "0.5.14"
 CUDA = "5"
 ChainRulesCore = "1.15"
diff --git a/src/Model.jl b/src/Model.jl
index 04e0128e9f..26b914b0e4 100644
--- a/src/Model.jl
+++ b/src/Model.jl
@@ -3,7 +3,7 @@
 # A physical specification of a model.
 # Contains the geometry information, but no discretization parameters.
 # The exact model used is defined by the list of terms.
-struct Model{T <: Real, VT <: Real}
+struct Model{T <: Real, VT <: Real} <: AbstractSystem{3}
     # T is the default type to express data, VT the corresponding bare value type (i.e. not dual)
 
     # Human-readable name for the model (like LDA, PBE, ...)
diff --git a/src/external/atomsbase.jl b/src/external/atomsbase.jl
index 3197d1ab1b..aa7343581d 100644
--- a/src/external/atomsbase.jl
+++ b/src/external/atomsbase.jl
@@ -1,6 +1,14 @@
 using AtomsBase
 # Key functionality to integrate DFTK and AtomsBase
 
+# implement AtomsBase interface directly on `Model` object
+Base.length(m::Model) = length(m.atoms)
+Base.getindex(m::Model, i) = m.atoms[i]
+position(m::Model, i) = DFTK.vector_red_to_cart(m, m.positions[i]) * u"a0_au"
+mass(m::Model, i) = m[i].mass
+species(m::Model, i) = m[i].symbol
+cell(m::Model) = PeriodicCell((m.lattice[:,1], m.lattice[:,2], m.lattice[:,3]), (true, true, true))
+
 function parse_system(system::AbstractSystem{D}) where {D}
     if !all(periodicity(system))
         error("DFTK only supports calculations with periodic boundary conditions.")