feos-org · prehner · Nov 8, 2025 · Oct 24, 2025 · Oct 31, 2025 · Oct 31, 2025
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
@@ -118,4 +118,4 @@ jobs:
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable
-      - run: cargo publish --token ${{ secrets.CRATES_IO_TOKEN }}
+      - run: cargo publish --workspace --exclude py_feos --token ${{ secrets.CRATES_IO_TOKEN }}
diff --git a/.github/workflows/release_core.yml b/.github/workflows/release_core.yml
diff --git a/.github/workflows/release_derive.yml b/.github/workflows/release_derive.yml
diff --git a/.github/workflows/release_dft.yml b/.github/workflows/release_dft.yml
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -6,6 +6,28 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.9.0] - 2025-11-08
+### Added
+- Integrated the functionalities of [`feos-ad`](https://github.com/feos-org/feos-ad). [#289](https://github.com/feos-org/feos/pull/289)
+    - In Rust: Full access to arbitrary derivatives of properties and phase equilibria with respect to model parameters. See, e.g., [`feos-campd`](https://github.com/feos-org/feos-campd) for an application to molecular design.
+    - In Python: Specialized functions for the parallel evaluation of relevant properties (vapor pressure, liquid density, bubble/dew point pressure) including the gradients with respect to model parameters for parameter estimations or the inclusion in backpropagation frameworks.
+- Implement pure-component multiparameter equations of state from CoolProp. [#301](https://github.com/feos-org/feos/pull/301)
+
+### Changed
+- :warning: Changed the format of parameter files. The contents of the old `model_record` field are now flattened into the `PureRecord`/`SegmentRecord`. [#233](https://github.com/feos-org/feos/pull/233)
+- Generalized the implementation of association to allow for arbitrarily many association sites per molecule or group and full control over each interaction. [#233](https://github.com/feos-org/feos/pull/233) [#290](https://github.com/feos-org/feos/pull/290)
+- Reimplemented the Python interface to avoid the necessity of having multiple classes with the same name.
+    - `feos.eos.State` and `feos.dft.State` (and analogous classes) are combined into `feos.State`. [#274](https://github.com/feos-org/feos/pull/274)
+    - All `feos.<model>.PureRecord` (and similar classes) are combined into `feos.PureRecord`. [#271](https://github.com/feos-org/feos/pull/271)
+- All Python classes are exported at the package root. [#309](https://github.com/feos-org/feos/pull/309)
+- Add initial density as optional argument to critical point algorithms. [#300](https://github.com/feos-org/feos/pull/300)
+
+### Packaging
+- Updated `quantity` dependency to 0.12.
+- Updated `num-dual` dependency to 0.12.
+- Updated `numpy`, `PyO3` and `pythonize` dependencies to 0.27.
+- Updated `nalgebra` dependency to 0.34.
+
 ## [0.8.0] - 2024-12-28
 ### Fixed
 - Fixed the handling of association records in combination with induced association in PC-SAFT [#264](https://github.com/feos-org/feos/pull/264)

diff --git a/Cargo.toml b/Cargo.toml
@@ -4,7 +4,7 @@ members = ["crates/*", "py-feos"]
 default-members = ["crates/feos"]
 
 [workspace.package]
-version = "0.8.0"
+version = "0.9.0"
 edition = "2024"
 authors = [
     "Gernot Bauer <bauer@itt.uni-stuttgart.de>",
@@ -22,7 +22,7 @@ keywords = [
 categories = ["science"]
 
 [workspace.dependencies]
-quantity = "0.11"
+quantity = "0.12"
 num-dual = "0.12"
 ndarray = "0.16"
 nalgebra = "0.34"
@@ -44,10 +44,10 @@ approx = "0.5"
 criterion = "0.7"
 paste = "1.0"
 
-feos-core = { version = "0.8", path = "crates/feos-core" }
-feos-dft = { version = "0.8", path = "crates/feos-dft" }
-feos-derive = { version = "0.6", path = "crates/feos-derive" }
-feos = { version = "0.8", path = "crates/feos" }
+feos-core = { version = "0.9", path = "crates/feos-core" }
+feos-dft = { version = "0.9", path = "crates/feos-dft" }
+feos-derive = { version = "0.9", path = "crates/feos-derive" }
+feos = { version = "0.9", path = "crates/feos" }
 
 [profile.release-lto]
 inherits = "release"

diff --git a/README.md b/README.md
@@ -1,33 +1,46 @@
 # FeOs - A Framework for Equations of State and Classical Density Functional Theory
 
-[![crate](https://img.shields.io/crates/v/feos.svg)](https://crates.io/crates/feos)
-[![documentation](https://docs.rs/feos/badge.svg)](https://docs.rs/feos)
-[![documentation](https://img.shields.io/badge/docs-github--pages-blue)](https://feos-org.github.io/feos/)
-[![repository](https://img.shields.io/pypi/v/feos)](https://pypi.org/project/feos/)
+[![crate](https://img.shields.io/crates/v/feos?logo=rust)](https://crates.io/crates/feos)
+[![documentation](https://img.shields.io/docsrs/feos?logo=rust)](https://docs.rs/feos)
+[![repository](https://img.shields.io/pypi/v/feos?logo=python)](https://pypi.org/project/feos/)
+[![documentation](https://img.shields.io/badge/docs-github--pages-blue?logo=python)](https://feos-org.github.io/feos/)
+[![FeOs Publication](https://img.shields.io/badge/DOI-10.1021/acs.iecr.2c04561-passing)](https://pubs.acs.org/doi/10.1021/acs.iecr.2c04561)
 
 The `FeOs` package provides Rust implementations of different equation of state and Helmholtz energy functional models and corresponding Python bindings.
 
 ```python
-from feos.eos import EquationOfState, State
-from feos.pcsaft import PcSaftParameters, PcSaftRecord
+import feos
+import si_units as si
 
 # PC-SAFT parameters for methanol (Gross and Sadowski 2002)
-record = PcSaftRecord(1.5255, 3.23, 188.9, kappa_ab=0.035176, epsilon_k_ab=2899.5, na=1, nb=1)
+record = feos.PureRecord(
+    feos.Identifier(name="methanol"),
+    molarweight=32.04,
+    m=1.5255,
+    sigma=3.23,
+    epsilon_k=188.9,
+    association_sites=[{
+      "kappa_ab": 0.035176,
+      "epsilon_k_ab": 2899.5,
+      "na": 1,
+      "nb": 1,
+    }]
+)
 
 # Build an equation of state
-parameters = PcSaftParameters.from_model_records([record])
-eos = EquationOfState.pcsaft(parameters)
+parameters = feos.Parameters.new_pure(record)
+eos = feos.EquationOfState.pcsaft(parameters)
 
 # Define thermodynamic conditions
-critical_point = State.critical_point(eos)
+critical_point = feos.State.critical_point(eos)
 
 # Compute properties
 p = critical_point.pressure()
 t = critical_point.temperature
-print(f'Critical point for methanol: T={t}, p={p}.')
+print(f"Critical point for methanol: T={t/si.KELVIN:.1f} K, p={p/si.BAR:.1f} bar.")
 ```
 ```terminal
-Critical point for methanol: T=531.5 K, p=10.7 MPa.
+Critical point for methanol: T=531.5 K, p=106.5 bar.
 ```
 
 ## Models
@@ -55,6 +68,14 @@ Other public repositories that implement models within the `FeOs` framework, but
 ## Parameters
 In addition to the source code for the Rust and Python packages, this repository contains JSON files with previously published [parameters](https://github.com/feos-org/feos/tree/main/parameters) for the different models including group contribution methods. The parameter files can be read directly from Rust or Python.
 
+> [!WARNING]
+> The format for parameter files changed between releases `0.8.0` and `0.9.0`. You find parameters for new versions in the [parameters](https://github.com/feos-org/feos/tree/main/parameters) directory and for versions up to `0.8.0` in the [parameters_old](https://github.com/feos-org/feos/tree/main/parameters_old) directory.<br><br>
+If you maintain your own parameter files, there are two adjustments you need to make when upgrading to `feos 0.9.0`:
+> - Flatten the contents of the `model_record` field directly into the pure or segment record.
+> - Move association parameters into a list called `association_sites`.
+>
+> The structure of the JSON files and the `PureRecord` and `SegmentRecord` classes in Python is identical.
+
 ## Properties and phase equilibria
 
 The crate makes use of [generalized (hyper-) dual numbers](https://github.com/itt-ustutt/num-dual) to generically calculate exact partial derivatives from Helmholtz energy equations of state. The derivatives are used to calculate
@@ -107,10 +128,11 @@ See the *Building from source* section for information about building the wheel
 
 ### Building from source
 
-To compile the code you need the Rust compiler and `maturin` (>=0.13,<0.14) installed.
+To compile the code you need the Rust compiler and `maturin` installed.
 To install the package directly into the active environment (virtualenv or conda), use
 
 ```
+cd py-feos
 maturin develop --release
 ```
 
@@ -119,7 +141,7 @@ which uses the `python` and `all_models` feature as specified in the `pyproject.
 Alternatively, you can specify the models or features that you want to include in the python package explicitly, e.g.
 
 ```
-maturin develop --release --features "python pcsaft dft"
+maturin develop --release --features "pcsaft dft"
 ```
 
 for the PC-SAFT equation of state and Helmholtz energy functional.
@@ -134,7 +156,7 @@ which will use the `python` and `all_models` features specified in the `pyprojec
 Use the following command to build a wheel with specific features:
 
 ```
-maturin build --profile="release-lto" --features "python ..."
+maturin build --profile="release-lto" --features "pcsaft ..."
 ```
 
 LTO increases compile times measurably but the resulting wheel is more performant and has a smaller size.
@@ -146,7 +168,7 @@ For a documentation of the Python API, Python examples, and a guide to the under
 
 ## Benchmarks
 
-Check out the [benches](https://github.com/feos-org/feos/tree/main/feos-benchmarks) directory for information about provided Rust benchmarks and how to run them.
+Check out the [benches](https://github.com/feos-org/feos/tree/main/crates/feos/benches) directory for information about provided Rust benchmarks and how to run them.
 
 ## Developers
 

diff --git a/crates/feos-core/CHANGELOG.md b/crates/feos-core/CHANGELOG.md
@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 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).
 
+> [!IMPORTANT]  
+> This file contains changes up to `feos-core` v0.8.0. For newer versions, changes are documented for the entire project rather than individual crates [here](../../CHANGELOG.md).
+
 ## Unreleased
 
 ## [0.8.0] - 2024-12-28

diff --git a/crates/feos-core/README.md b/crates/feos-core/README.md
@@ -10,14 +10,4 @@ The crate makes use of [generalized (hyper-) dual numbers](https://github.com/it
 - **critical points**,
 - and **phase equilibria**.
 
-In addition to that, utilities are provided to assist in the handling of **parameters** for both molecular equations of state and (homosegmented) group contribution methods. Mainly as a simple test case, a **cubic** equation of state is published as part of this crate. Implementations of more sophisticated models can be found in the [feos](https://github.com/feos-org/feos) repository.
-
-For information on how to implement your own equation of state, check out the [documentation](https://feos-org.github.io/feos/rustguide/index.html).
-
-## Installation
-
-Add this to your `Cargo.toml`
-
-```toml
-[dependencies]
-feos-core = "0.7"
+In addition to that, utilities are provided to assist in the handling of **parameters** for both molecular equations of state and (homosegmented) group contribution methods. Mainly as a simple test case, a **cubic** equation of state is published as part of this crate. Implementations of more sophisticated models can be found in the [feos](https://crates.io/crates/feos) crate.
diff --git a/crates/feos-core/src/lib.rs b/crates/feos-core/src/lib.rs
@@ -45,22 +45,17 @@ pub use phase_equilibria::{PhaseEquilibrium, TemperatureOrPressure};
 pub use state::{Contributions, DensityInitialization, State, StateBuilder, StateHD, StateVec};
 
 /// Level of detail in the iteration output.
-#[derive(Copy, Clone, PartialOrd, PartialEq, Eq)]
+#[derive(Copy, Clone, PartialOrd, PartialEq, Eq, Default)]
 pub enum Verbosity {
     /// Do not print output.
+    #[default]
     None,
     /// Print information about the success of failure of the iteration.
     Result,
     /// Print a detailed outpur for every iteration.
     Iter,
 }
 
-impl Default for Verbosity {
-    fn default() -> Self {
-        Self::None
-    }
-}
-
 /// Options for the various phase equilibria solvers.
 ///
 /// If the values are [None], solver specific default

diff --git a/crates/feos-derive/Cargo.toml b/crates/feos-derive/Cargo.toml
@@ -1,22 +1,14 @@
 [package]
 name = "feos-derive"
-version = "0.6.0"
-authors = [
-    "Gernot Bauer <bauer@itt.uni-stuttgart.de>",
-    "Philipp Rehner <prehner@ethz.ch>",
-]
-edition = "2021"
-readme = "README.md"
-description = "Macros for the EquationOfState and HelmholtzEnergyFunctional traits in FeOs"
-license = "MIT OR Apache-2.0"
-homepage = "https://github.com/feos-org"
-repository = "https://github.com/feos-org/feos"
-keywords = [
-    "physics",
-    "thermodynamics",
-    "equations_of_state",
-    "phase_equilibria",
-]
+edition.workspace = true
+version.workspace = true
+authors.workspace = true
+homepage.workspace = true
+license.workspace = true
+repository.workspace = true
+keywords.workspace = true
+categories.workspace = true
+description = "Macros for the automatic implementation of traits in FeOs"
 
 [lib]
 proc-macro = true

diff --git a/crates/feos-derive/README.md b/crates/feos-derive/README.md
@@ -9,6 +9,6 @@
 
 ## What it does
 
-The `feos-derive` crate contains two macros that provide boilerplate for the implementation of the `EquationOfState` and the `HelmholtzEnergyFunctional` trait for the `EosVariant` and `FunctionalVariant` enums of the `feos` crate. With these macros, new equations of state and functionals can be added to the variants without any further implementations needed.
+The `feos-derive` crate contains macros that provide boilerplate for the implementation of several traits from `feos-core` and `feos-dft` for the FFI conform enums in `feos`. With these macros, new equations of state and functionals can be added straightforwardly to the Python interface or other FFIs.
 
 
diff --git a/crates/feos-dft/CHANGELOG.md b/crates/feos-dft/CHANGELOG.md
@@ -4,6 +4,9 @@ All notable changes to this project will be documented in this file.
 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).
 
+> [!IMPORTANT]
+> This file contains changes up to `feos-dft` v0.8.0. For newer versions, changes are documented for the entire project rather than individual crates [here](../../CHANGELOG.md).
+
 ## [Unreleased]
 
 ## [0.8.0] - 2024-12-28

diff --git a/crates/feos-dft/Cargo.toml b/crates/feos-dft/Cargo.toml
@@ -9,7 +9,6 @@ repository.workspace = true
 keywords.workspace = true
 categories.workspace = true
 description = "Generic classical DFT implementations for the `feos` project."
-exclude = ["/.github/*", "*.ipynb"]
 
 [package.metadata.docs.rs]
 rustdoc-args = ["--html-in-header", "./docs-header.html"]

diff --git a/crates/feos-dft/README.md b/crates/feos-dft/README.md
@@ -10,12 +10,3 @@ The crate makes use of efficient numerical methods to calculate density profiles
 - Automatic calculation of partial derivatives of Helmholtz energy densities (including temperature derivatives) using automatic differentiation with [generalized (hyper-) dual numbers](https://github.com/itt-ustutt/num-dual).
 - Modeling of heterosegmented molecules, including branched molecules.
 - Functionalities for calculating surface tensions, adsorption isotherms, pair correlation functions, and solvation free energies.
-
-## Installation
-
-Add this to your `Cargo.toml`
-
-```toml
-[dependencies]
-feos-dft = "0.7"
-```
diff --git a/crates/feos/README.md b/crates/feos/README.md
@@ -0,0 +1 @@
+../../README.md
diff --git a/crates/feos/src/pcsaft/eos/polar.rs b/crates/feos/src/pcsaft/eos/polar.rs
@@ -91,7 +91,6 @@ pub enum Multipole {
 }
 
 impl MeanSegmentNumbers {
-    #[expect(clippy::needless_range_loop)]
     pub fn new(parameters: &PcSaftPars, polarity: Multipole) -> Self {
         let (npoles, comp) = match polarity {
             Multipole::Dipole => (parameters.ndipole, &parameters.dipole_comp),

diff --git a/docs/conf.py b/docs/conf.py
@@ -42,9 +42,5 @@
 
 # -- Options for HTML output -------------------------------------------------
 html_theme = 'furo'
-html_title = "FeOs"
-html_static_path = ['_static']
-html_css_files = [
-    'style.css',
-]
+html_title = f'FeOs v{feos.__version__}'
 
diff --git a/license-apache b/license-apache
@@ -1,4 +1,4 @@
-   Copyright (c) 2021-present feos-org and Contributors.  https://github.com/feos-org/feos
+   Copyright (c) 2021-2025 feos-org and Contributors.  https://github.com/feos-org/feos
 
                                  Apache License
                            Version 2.0, January 2004
Original file line number	Diff line number	Diff line change
Expand Up		@@ -9,6 +9,6 @@

		## What it does

		The `feos-derive` crate contains two macros that provide boilerplate for the implementation of the `EquationOfState` and the `HelmholtzEnergyFunctional` trait for the `EosVariant` and `FunctionalVariant` enums of the `feos` crate. With these macros, new equations of state and functionals can be added to the variants without any further implementations needed.
		The `feos-derive` crate contains macros that provide boilerplate for the implementation of several traits from `feos-core` and `feos-dft` for the FFI conform enums in `feos`. With these macros, new equations of state and functionals can be added straightforwardly to the Python interface or other FFIs.