diff --git a/Cargo.toml b/Cargo.toml
index 6eae03c0a..7d4446da0 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -56,6 +56,6 @@ pcsaft = ["association"]
 gc_pcsaft = ["association"]
 uvtheory = ["lazy_static"]
 pets = []
-rayon = ["dep:rayon", "ndarray/rayon", "feos-core/rayon"]
+rayon = ["dep:rayon", "ndarray/rayon", "feos-core/rayon", "feos-dft?/rayon"]
 python = ["pyo3", "numpy", "feos-core/python", "feos-dft?/python", "rayon"]
 all_models = ["dft", "estimator", "pcsaft", "gc_pcsaft", "uvtheory", "pets"]
diff --git a/feos-dft/CHANGELOG.md b/feos-dft/CHANGELOG.md
index 6e44fd674..8cf352dc0 100644
--- a/feos-dft/CHANGELOG.md
+++ b/feos-dft/CHANGELOG.md
@@ -5,6 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Changed
+- Added `Send` and `Sync` as supertraits to `HelmholtzEnergyFunctional` and all related traits. [#57](https://github.com/feos-org/feos/pull/57)
+- Renamed the `3d_dft` feature to `rayon` in accordance to the other feos crates. [#62](https://github.com/feos-org/feos/pull/62)
 
 ## [0.3.2] - 2022-10-13
 ### Changed
diff --git a/feos-dft/Cargo.toml b/feos-dft/Cargo.toml
index b2fc7e40c..96581316a 100644
--- a/feos-dft/Cargo.toml
+++ b/feos-dft/Cargo.toml
@@ -14,7 +14,7 @@ exclude = ["/.github/*", "*.ipynb"]
 
 [package.metadata.docs.rs]
 rustdoc-args = [ "--html-in-header", "./docs-header.html" ]
-features = [ "3d_dft" ]
+features = [ "rayon" ]
 
 [dependencies]
 quantity = { version = "0.5", features = ["linalg"] }
@@ -33,5 +33,5 @@ pyo3 = { version = "0.16", optional = true }
 
 [features]
 default = []
-3d_dft = ["gauss-quad", "ndarray/rayon"]
-python = ["pyo3", "numpy", "feos-core/python", "3d_dft"]
+rayon = ["gauss-quad", "ndarray/rayon"]
+python = ["pyo3", "numpy", "feos-core/python", "rayon"]
diff --git a/feos-dft/src/adsorption/external_potential.rs b/feos-dft/src/adsorption/external_potential.rs
index 2f01bd973..51ac41ad4 100644
--- a/feos-dft/src/adsorption/external_potential.rs
+++ b/feos-dft/src/adsorption/external_potential.rs
@@ -1,12 +1,12 @@
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 use crate::adsorption::fea_potential::calculate_fea_potential;
 use crate::functional::HelmholtzEnergyFunctional;
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 use crate::geometry::Geometry;
 use feos_core::EosUnit;
 use libm::tgamma;
 use ndarray::{Array1, Array2, Axis as Axis_nd};
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 use quantity::{QuantityArray2, QuantityScalar};
 use std::{f64::consts::PI, marker::PhantomData};
 
@@ -52,7 +52,7 @@ pub enum ExternalPotential<U> {
         rho_s: f64,
     },
     /// Free-energy averaged potential:
-    #[cfg(feature = "3d_dft")]
+    #[cfg(feature = "rayon")]
     FreeEnergyAveraged {
         coordinates: QuantityArray2<U>,
         sigma_ss: Array1<f64>,
@@ -192,7 +192,7 @@ impl<U: EosUnit> ExternalPotential<U> {
                             * (2.0 * (sigma_sf[i] / z_grid).mapv(|x| x.powi(9))
                                 - 15.0 * (sigma_sf[i] / z_grid).mapv(|x| x.powi(3))))
                 }
-                #[cfg(feature = "3d_dft")]
+                #[cfg(feature = "rayon")]
                 Self::FreeEnergyAveraged {
                     coordinates,
                     sigma_ss,
@@ -358,7 +358,7 @@ impl<U: EosUnit> ExternalPotential<U> {
                             * sigma_sf[i].powi(3)
                             * *rho_s)
                 }
-                #[cfg(feature = "3d_dft")]
+                #[cfg(feature = "rayon")]
                 Self::FreeEnergyAveraged {
                     coordinates,
                     sigma_ss,
@@ -548,7 +548,7 @@ impl<U: EosUnit> ExternalPotential<U> {
                             * (2.0 / 5.0 * sum_n(10, r_grid, sigma_sf[i], pore_size)
                                 - sum_n(4, r_grid, sigma_sf[i], pore_size)))
                 }
-                #[cfg(feature = "3d_dft")]
+                #[cfg(feature = "rayon")]
                 Self::FreeEnergyAveraged {
                     coordinates,
                     sigma_ss,
diff --git a/feos-dft/src/adsorption/mod.rs b/feos-dft/src/adsorption/mod.rs
index 3a6ac50f2..12885984d 100644
--- a/feos-dft/src/adsorption/mod.rs
+++ b/feos-dft/src/adsorption/mod.rs
@@ -11,15 +11,15 @@ use std::iter;
 use std::sync::Arc;
 
 mod external_potential;
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 mod fea_potential;
 mod pore;
 pub use external_potential::{ExternalPotential, FluidParameters};
 pub use pore::{Pore1D, PoreProfile, PoreProfile1D, PoreSpecification};
 
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 mod pore3d;
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 pub use pore3d::{Pore3D, PoreProfile3D};
 
 const MAX_ITER_ADSORPTION_EQUILIBRIUM: usize = 50;
diff --git a/feos-dft/src/profile.rs b/feos-dft/src/profile.rs
index af24b20f4..4b7f09970 100644
--- a/feos-dft/src/profile.rs
+++ b/feos-dft/src/profile.rs
@@ -16,7 +16,7 @@ use std::ops::MulAssign;
 use std::sync::Arc;
 
 pub(crate) const MAX_POTENTIAL: f64 = 50.0;
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 pub(crate) const CUTOFF_RADIUS: f64 = 14.0;
 
 /// General specifications for the chemical potential in a DFT calculation.
diff --git a/feos-dft/src/solvation/mod.rs b/feos-dft/src/solvation/mod.rs
index 482d097f8..e5f6dcb35 100644
--- a/feos-dft/src/solvation/mod.rs
+++ b/feos-dft/src/solvation/mod.rs
@@ -2,7 +2,7 @@
 mod pair_correlation;
 pub use pair_correlation::{PairCorrelation, PairPotential};
 
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 mod solvation_profile;
-#[cfg(feature = "3d_dft")]
+#[cfg(feature = "rayon")]
 pub use solvation_profile::SolvationProfile;