diff --git a/feos-core/CHANGELOG.md b/feos-core/CHANGELOG.md
index 33c06cafe..f84d3dab4 100644
--- a/feos-core/CHANGELOG.md
+++ b/feos-core/CHANGELOG.md
@@ -5,6 +5,10 @@ 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
+- Made binary parameters in `from_records` Python routine an `Option`. [#35](https://github.com/feos-org/feos/pull/35)
+- Added panic with message when parsing missing Identifiers variants. [#35](https://github.com/feos-org/feos/pull/35)
+
 ### Fixed
 - Avoid panicking when calculating `ResidualNpt` properties of states with negative pressures. [#42](https://github.com/feos-org/feos/pull/42)
 
diff --git a/feos-core/src/parameter/mod.rs b/feos-core/src/parameter/mod.rs
index bee40af34..2df800c86 100644
--- a/feos-core/src/parameter/mod.rs
+++ b/feos-core/src/parameter/mod.rs
@@ -92,8 +92,20 @@ where
         };
         let n = pure_records.len();
         Array2::from_shape_fn([n, n], |(i, j)| {
-            let id1 = pure_records[i].identifier.as_string(search_option).unwrap();
-            let id2 = pure_records[j].identifier.as_string(search_option).unwrap();
+            let id1 = pure_records[i]
+                .identifier
+                .as_string(search_option)
+                .expect(&format!(
+                    "No identifier for given search_option for pure record {}.",
+                    i
+                ));
+            let id2 = pure_records[j]
+                .identifier
+                .as_string(search_option)
+                .expect(&format!(
+                    "No identifier for given search_option for pure record {}.",
+                    j
+                ));
             binary_map
                 .get(&(id1.clone(), id2.clone()))
                 .or_else(|| binary_map.get(&(id2, id1)))
diff --git a/feos-core/src/python/cubic.rs b/feos-core/src/python/cubic.rs
index d23f9f83d..a6f51d4ec 100644
--- a/feos-core/src/python/cubic.rs
+++ b/feos-core/src/python/cubic.rs
@@ -6,6 +6,7 @@ use crate::parameter::{
 use crate::python::joback::PyJobackRecord;
 use crate::python::parameter::PyIdentifier;
 use crate::*;
+use ndarray::Array2;
 use numpy::PyReadonlyArray2;
 use pyo3::exceptions::PyTypeError;
 use pyo3::prelude::*;
diff --git a/feos-core/src/python/parameter.rs b/feos-core/src/python/parameter.rs
index b9b87e8c6..e486db91a 100644
--- a/feos-core/src/python/parameter.rs
+++ b/feos-core/src/python/parameter.rs
@@ -542,7 +542,7 @@ macro_rules! impl_parameter {
             /// ----------
             /// pure_records : [PureRecord]
             ///     A list of pure component parameters.
-            /// binary_records : numpy.ndarray[float] or List[BinaryRecord]
+            /// binary_records : numpy.ndarray[float] or List[BinaryRecord], optional
             ///     A matrix of binary interaction parameters or a list
             ///     containing records for binary interactions.
             /// search_option : IdentifierOption, optional, defaults to IdentifierOption.Name
@@ -551,25 +551,33 @@ macro_rules! impl_parameter {
             #[pyo3(text_signature = "(pure_records, binary_records, search_option)")]
             fn from_records(
                 pure_records: Vec<PyPureRecord>,
-                binary_records: &PyAny,
+                binary_records: Option<&PyAny>,
                 search_option: Option<IdentifierOption>,
             ) -> PyResult<Self> {
                 let prs = pure_records.into_iter().map(|pr| pr.0).collect();
-                let brs = if let Ok(br) = binary_records.extract::<PyReadonlyArray2<f64>>() {
-                    Ok(br.to_owned_array().mapv(|r| r.try_into().unwrap()))
-                } else if let Ok(br) = binary_records.extract::<Vec<PyBinaryRecord>>() {
-                    let brs: Vec<_> = br.into_iter().map(|br| br.0).collect();
-                    Ok(<$parameter>::binary_matrix_from_records(
-                        &prs,
-                        &brs,
-                        search_option.unwrap_or(IdentifierOption::Name),
-                    ))
+                if let Some(binary_records) = binary_records {
+                    let brs = if let Ok(br) = binary_records.extract::<PyReadonlyArray2<f64>>() {
+                        Ok(br.to_owned_array().mapv(|r| r.try_into().unwrap()))
+                    } else if let Ok(br) = binary_records.extract::<Vec<PyBinaryRecord>>() {
+                        let brs: Vec<_> = br.into_iter().map(|br| br.0).collect();
+                        Ok(<$parameter>::binary_matrix_from_records(
+                            &prs,
+                            &brs,
+                            search_option.unwrap_or(IdentifierOption::Name),
+                        ))
+                    } else {
+                        Err(PyErr::new::<PyTypeError, _>(format!(
+                            "Could not parse binary input!"
+                        )))
+                    };
+                    Ok(Self(Rc::new(<$parameter>::from_records(prs, brs.unwrap()))))
                 } else {
-                    Err(PyErr::new::<PyTypeError, _>(format!(
-                        "Could not parse binary input!"
-                    )))
-                };
-                Ok(Self(Rc::new(<$parameter>::from_records(prs, brs.unwrap()))))
+                    let n = prs.len();
+                    Ok(Self(Rc::new(<$parameter>::from_records(
+                        prs,
+                        Array2::from_elem([n, n], <$parameter as Parameter>::Binary::default()),
+                    ))))
+                }
             }
 
             /// Creates parameters for a pure component from a pure record.
diff --git a/src/gc_pcsaft/dft/parameter.rs b/src/gc_pcsaft/dft/parameter.rs
index c70f7f33a..0cd2c36d0 100644
--- a/src/gc_pcsaft/dft/parameter.rs
+++ b/src/gc_pcsaft/dft/parameter.rs
@@ -8,7 +8,6 @@ use indexmap::IndexMap;
 use ndarray::{Array1, Array2};
 use petgraph::dot::{Config, Dot};
 use petgraph::graph::{Graph, UnGraph};
-use std::fmt::Write;
 
 /// psi Parameter for heterosegmented DFT (Mairhofer2018)
 const PSI_GC_DFT: f64 = 1.5357;
diff --git a/src/pcsaft/python.rs b/src/pcsaft/python.rs
index 95a0619d9..a8eaaa640 100644
--- a/src/pcsaft/python.rs
+++ b/src/pcsaft/python.rs
@@ -8,6 +8,7 @@ use feos_core::parameter::{
 use feos_core::python::joback::PyJobackRecord;
 use feos_core::python::parameter::*;
 use feos_core::*;
+use ndarray::Array2;
 use numpy::{PyArray2, PyReadonlyArray2, ToPyArray};
 use pyo3::exceptions::PyTypeError;
 use pyo3::prelude::*;