diff --git a/rust/trexio/src/bitfield.rs b/rust/trexio/src/bitfield.rs
index fee35da..54ee6d3 100644
--- a/rust/trexio/src/bitfield.rs
+++ b/rust/trexio/src/bitfield.rs
@@ -35,6 +35,10 @@ impl Bitfield {
         }
     }
 
+    pub fn from_vec(v: &[i64]) -> Bitfield {
+        Bitfield { data: v.to_vec() }
+    }
+
     pub fn from_alpha_beta(alpha: &Bitfield, beta: &Bitfield) -> Bitfield {
         if alpha.data.len() != beta.data.len() {
             panic!("alpha and beta parts have different lengths");
@@ -98,6 +102,11 @@ impl Bitfield {
         result
     }
 
+    /// Converts the bitfield into a vector
+    pub fn as_vec(&self) -> &[i64] {
+        &self.data
+    }
+
     /// Converts the determinant into a list of orbital indices (0-based)
     pub fn to_orbital_list_up_dn(&self) -> (Vec<usize>, Vec<usize>) {
 
diff --git a/rust/trexio/src/lib.rs b/rust/trexio/src/lib.rs
index 89f704f..431a189 100644
--- a/rust/trexio/src/lib.rs
+++ b/rust/trexio/src/lib.rs
@@ -98,18 +98,31 @@ impl File {
          rc_return(num, rc)
     }
 
-/*
-    pub fn read_determinant_list(&self, offset_file: usize, dset: Vec<Bitfield>) -> Result<usize, ExitCode> {
+    pub fn write_determinant_list(&self, offset_file: usize, determinants: &[Bitfield]) -> Result<(), ExitCode> {
+        let n_int = self.get_int64_num()?;
+        match determinants.len() {
+            0 => return Ok(()),
+            _ => if determinants[0].as_vec().len() != 2*n_int {
+                panic!("Inconsistent values of n_int")
+            }
+        };
+        let offset_file: i64 = offset_file.try_into().expect("try_into failed in read_determinant_list");
+        let buffer_size: i64 = determinants.len().try_into().expect("try_into failed in read_determinant_list");
+        let mut one_d_array: Vec<i64> = Vec::with_capacity(determinants.len() * n_int);
+        for det in determinants.iter() {
+          for i in det.as_vec().iter() {
+            one_d_array.push(i.clone());
+          }
+        }
+        let dset: *const i64 = one_d_array.as_ptr() as *const i64;
         let rc = unsafe {
-            let offset_file: i64 = offset_file;
-            let buffer_size: *mut i64 = dset.len().try_into().expect("try_into failed in read_determinant_list");
-            let dset: *mut i64 = dset.to_c().as_mut_ptr();
-            c::trexio_read_determinant_list(self.ptr, offset_file, buffer_size, dset)
+            c::trexio_write_determinant_list(self.ptr, offset_file, buffer_size, dset)
          };
+         rc_return((), rc)
     }
-    */
 
 }
+
 include!("generated.rs");
 
 
diff --git a/rust/trexio/src/test.rs b/rust/trexio/src/test.rs
index 766fe45..5e8f46a 100644
--- a/rust/trexio/src/test.rs
+++ b/rust/trexio/src/test.rs
@@ -1,13 +1,14 @@
 use trexio::back_end::BackEnd;
+use trexio::bitfield::Bitfield;
 
 pub fn test_write(file_name: &str, back_end: BackEnd) -> Result<(), trexio::ExitCode> {
 
     let () = trexio::info()?;
 
     // Prepare data to be written
+
     let n_buffers = 5;
     let buf_size_sparse = 100/n_buffers;
-    let buf_size_det    = 50/n_buffers;
     let mut value_sparse_ao_2e_int_eri = vec![0.0f64 ; 100];
     let mut index_sparse_ao_2e_int_eri = vec![0i32 ; 400];
     for i in 0..100 {
@@ -98,6 +99,26 @@ pub fn test_write(file_name: &str, back_end: BackEnd) -> Result<(), trexio::Exit
     }
     trex_file.write_mo_spin(spin)?;
 
+    // Determinants
+    //
+    let det_num = 50;
+    let mut det_list = Vec::with_capacity(det_num);
+    for i in 0..det_num {
+        let mut d = [0i64 ; 6 ];
+        for j in 0..6 {
+            d[j] = 6*(i as i64)+(j as i64);
+        }
+        det_list.push( Bitfield::from_vec(&d) );
+    }
+
+    let n_buffers = 5;
+    let buf_size_det    = 50/n_buffers;
+    let mut offset = 0;
+    for i in 0..n_buffers {
+        trex_file.write_determinant_list(offset, &det_list[offset..offset+buf_size_det])?;
+        offset += buf_size_det;
+    }
+
 
     trex_file.close()