Removed the check for multiple polar/associating groups in homo gc constructor

prehner · prehner · commit 7fdb57ac03f0 · 2022-03-31T20:21:08.000+02:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - `PcSaftFunctional` now always uses `Joback` as ideal gas model if parameters are available. [#25](https://github.com/feos-org/feos-pcsaft/pull/25)
 
+### Changed
+- Building Pc-SAFT parameters from segments does not check anymore, whether multiple polar or associating groups are present. [#33](https://github.com/feos-org/feos-pcsaft/pull/33)
+
 ## [0.1.0] - 2022-01-12
 ### Added
 - Initial release
diff --git a/src/parameters.rs b/src/parameters.rs
@@ -56,40 +56,22 @@ impl FromSegments for PcSaftRecord {
             epsilon_k += s.m * s.epsilon_k * *n;
         });
 
-        // We do not allow more than a single segment for q, mu, kappa_ab, epsilon_k_ab
-        let q: Vec<f64> = segments.iter().filter_map(|s| s.0.q).collect();
-        let q = match q.len() {
-            0 => None,
-            1 => Some(q[0]),
-            _ => panic!("More than one segment with quadrupole moment."),
-        };
+        let q = segments
+            .iter()
+            .filter_map(|(s, n)| s.q.map(|q| q * *n))
+            .reduce(|a, b| a + b);
         let mu = segments
             .iter()
             .filter_map(|(s, n)| s.mu.map(|mu| mu * *n))
             .reduce(|a, b| a + b);
-        // let mu = match mu.len() {
-        //     0 => None,
-        //     1 => Some(mu[0]),
-        //     _ => panic!("More than one segment with dipole moment."),
-        // };
         let kappa_ab = segments
             .iter()
             .filter_map(|(s, n)| s.kappa_ab.map(|k| k * *n))
             .reduce(|a, b| a + b);
-        // let kappa_ab = match kappa_ab.len() {
-        //     0 => None,
-        //     1 => Some(kappa_ab[0]),
-        //     _ => panic!("More than one segment with association site."),
-        // };
         let epsilon_k_ab = segments
             .iter()
             .filter_map(|(s, n)| s.epsilon_k_ab.map(|e| e * *n))
             .reduce(|a, b| a + b);
-        // let epsilon_k_ab = match epsilon_k_ab.len() {
-        //     0 => None,
-        //     1 => Some(epsilon_k_ab[0]),
-        //     _ => panic!("More than one segment with association site"),
-        // };
         let na = segments
             .iter()
             .filter_map(|(s, n)| s.na.map(|na| na * *n))
@@ -98,6 +80,7 @@ impl FromSegments for PcSaftRecord {
             .iter()
             .filter_map(|(s, n)| s.nb.map(|nb| nb * *n))
             .reduce(|a, b| a + b);
+
         Self {
             m,
             sigma: (sigma3 / m).cbrt(),
