diff --git a/rascaline-c-api/src/calculator.rs b/rascaline-c-api/src/calculator.rs
index 8a512f05a..234a2aba0 100644
--- a/rascaline-c-api/src/calculator.rs
+++ b/rascaline-c-api/src/calculator.rs
@@ -54,14 +54,13 @@ pub unsafe extern fn rascal_calculator(name: *const c_char, parameters: *const c
     let mut raw = std::ptr::null_mut();
     let unwind_wrapper = std::panic::AssertUnwindSafe(&mut raw);
     let status = catch_unwind(move || {
-        let unwind_wrapper = unwind_wrapper;
-
         check_pointers!(name, parameters);
         let name = CStr::from_ptr(name).to_str()?;
         let parameters = CStr::from_ptr(parameters).to_str()?;
         let calculator = Calculator::new(name, parameters.to_owned())?;
         let boxed = Box::new(rascal_calculator_t(calculator));
 
+        let _ = &unwind_wrapper;
         *unwind_wrapper.0 = Box::into_raw(boxed);
         Ok(())
     });
diff --git a/rascaline-c-api/src/status.rs b/rascaline-c-api/src/status.rs
index a861323bc..2dd255a67 100644
--- a/rascaline-c-api/src/status.rs
+++ b/rascaline-c-api/src/status.rs
@@ -84,7 +84,7 @@ impl From<Error> for rascal_status_t {
 /// the error into `rascal_status_t`.
 pub fn catch_unwind<F>(function: F) -> rascal_status_t where F: FnOnce() -> Result<(), Error> + UnwindSafe {
     match std::panic::catch_unwind(function) {
-        Ok(Ok(_)) => rascal_status_t(RASCAL_SUCCESS),
+        Ok(Ok(())) => rascal_status_t(RASCAL_SUCCESS),
         Ok(Err(error)) => error.into(),
         Err(error) => Error::from(error).into()
     }
diff --git a/rascaline/src/calculators/neighbor_list.rs b/rascaline/src/calculators/neighbor_list.rs
index c092b4753..fc19c22cb 100644
--- a/rascaline/src/calculators/neighbor_list.rs
+++ b/rascaline/src/calculators/neighbor_list.rs
@@ -500,7 +500,7 @@ impl FullNeighborList {
             system.compute_neighbors(self.cutoff)?;
             let species = system.species()?;
 
-            for pair in system.pairs()?.iter() {
+            for pair in system.pairs()? {
                 let first_block_i = descriptor.keys().position(&[
                     species[pair.first].into(), species[pair.second].into()
                 ]);
diff --git a/rascaline/src/calculators/soap/spherical_expansion.rs b/rascaline/src/calculators/soap/spherical_expansion.rs
index 1601e2f35..b62cfa37d 100644
--- a/rascaline/src/calculators/soap/spherical_expansion.rs
+++ b/rascaline/src/calculators/soap/spherical_expansion.rs
@@ -189,7 +189,7 @@ impl SphericalExpansion {
                 let neighbor_i = pair.second;
 
                 result.pair_to_pair_ids.entry((pair.first, pair.second))
-                    .or_insert_with(Vec::new)
+                    .or_default()
                     .push(pair_id);
 
                 let species_neighbor_i = result.species_mapping[&species[neighbor_i]];
@@ -253,7 +253,7 @@ impl SphericalExpansion {
                 let neighbor_i = pair.first;
 
                 result.pair_to_pair_ids.entry((pair.second, pair.first))
-                    .or_insert_with(Vec::new)
+                    .or_default()
                     .push(pair_id);