diff --git a/Cargo.toml b/Cargo.toml
index 1086859..93aeeb6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,7 +1,7 @@
 [package]
 name = "rdkit"
 version = "0.4.12"
-edition = "2021"
+edition = "2024"
 authors = ["Xavier Lange <xrlange@gmail.com>", "Javier Pineda <javierjpineda13@gmail.com"]
 license = "MIT"
 description = "High level RDKit functionality for rust"
@@ -17,7 +17,7 @@ cxx = "1"
 flate2 = "1"
 log = "0.4"
 rdkit-sys = { path = "rdkit-sys", version = "0.4.9" }
-thiserror = "1"
+thiserror = "2"
 
 [dev-dependencies]
-env_logger = "0.9.0"
+env_logger = "0.11"
diff --git a/README.md b/README.md
index a3a1a69..137cfa3 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@ RDKit
 ---
 
 A high-level library for performing common RDKit tasks such as SMILES parsing, molecule normalization, etc. Uses
-the C++ API via bindings from [rdkit-sys](https://crates.io/crate/rdkit-sys).
+the C++ API via bindings from [rdkit-sys](https://crates.io/crates/rdkit-sys).
 
 Notice: Requires rdkit 2023.09.1 or higher (like Ubuntu Noble 24.04)
 
diff --git a/benches/atom_iteration_benchmark.rs b/benches/atom_iteration_benchmark.rs
new file mode 100644
index 0000000..47b5927
--- /dev/null
+++ b/benches/atom_iteration_benchmark.rs
@@ -0,0 +1,102 @@
+#![allow(soft_unstable)]
+#![feature(test)]
+extern crate test;
+
+use rdkit::ROMol;
+
+/// Drug-like molecules of varying size for realistic benchmarking.
+/// These cover common pharmaceutical scaffolds and natural products.
+const SMILES_SET: &[&str] = &[
+    // aspirin
+    "CC(=O)Oc1ccccc1C(=O)O",
+    // ibuprofen
+    "CC(C)Cc1ccc(cc1)C(C)C(=O)O",
+    // caffeine
+    "Cn1c(=O)c2c(ncn2C)n(C)c1=O",
+    // diazepam
+    "O=C1CN=C(c2ccccc2)c2cc(Cl)ccc2N1C",
+    // atorvastatin (lipitor)
+    "CC(C)c1c(C(=O)Nc2ccccc2)c(-c2ccccc2)c(-c2ccc(F)cc2)n1CC[C@@H](O)C[C@@H](O)CC(=O)O",
+    // taxol core
+    "CC1=C2C(OC(=O)c3ccccc3)C(O)C4(OC(=O)C(O)(CC(OC(=O)c5ccccc5)C1O)C24C)C(=O)c1ccc(OC)cc1",
+    // vancomycin fragment
+    "OC1C(O)C(OC2C(O)C(O)C(O)C(CO)O2)OC(CO)C1NC(=O)C1CC(O)CN1C(=O)C(NC(=O)C1CC(=O)NC(=O)C1O)C(O)c1ccc(O)cc1",
+];
+
+/// Baseline: SMILES parsing cost.
+#[bench]
+fn bench_parse_smiles(b: &mut test::bench::Bencher) {
+    b.iter(|| {
+        for smiles in SMILES_SET {
+            test::black_box(ROMol::from_smiles(smiles).unwrap());
+        }
+    });
+}
+
+/// Iterate all atoms via atom_ref (&self), read 7 properties per atom.
+/// This is the realistic featurization workload.
+#[bench]
+fn bench_atom_ref_all_properties(b: &mut test::bench::Bencher) {
+    let mols: Vec<ROMol> = SMILES_SET
+        .iter()
+        .map(|s| ROMol::from_smiles(s).unwrap())
+        .collect();
+
+    b.iter(|| {
+        for mol in &mols {
+            let n = mol.num_atoms(true);
+            for i in 0..n {
+                let atom = mol.atom_ref(i);
+                test::black_box(atom.symbol());
+                test::black_box(atom.get_atomic_num());
+                test::black_box(atom.get_formal_charge());
+                test::black_box(atom.get_is_aromatic());
+                test::black_box(atom.get_hybridization_type());
+                test::black_box(atom.get_degree());
+                test::black_box(atom.get_total_num_hs());
+            }
+        }
+    });
+}
+
+/// Same workload via atom_with_idx (&mut self).
+/// Regression guard: should be the same speed as atom_ref.
+#[bench]
+fn bench_atom_mut_all_properties(b: &mut test::bench::Bencher) {
+    let mut mols: Vec<ROMol> = SMILES_SET
+        .iter()
+        .map(|s| ROMol::from_smiles(s).unwrap())
+        .collect();
+
+    b.iter(|| {
+        for mol in &mut mols {
+            let n = mol.num_atoms(true);
+            for i in 0..n {
+                let atom = mol.atom_with_idx(i);
+                test::black_box(atom.symbol());
+                test::black_box(atom.get_atomic_num());
+                test::black_box(atom.get_formal_charge());
+                test::black_box(atom.get_is_aromatic());
+                test::black_box(atom.get_hybridization_type());
+                test::black_box(atom.get_degree());
+                test::black_box(atom.get_total_num_hs());
+            }
+        }
+    });
+}
+
+/// Clone cost alone. Useful for understanding the cost of cloning
+/// molecules when only &ROMol is available but mutation is needed.
+#[bench]
+fn bench_clone_molecules(b: &mut test::bench::Bencher) {
+    let mols: Vec<ROMol> = SMILES_SET
+        .iter()
+        .map(|s| ROMol::from_smiles(s).unwrap())
+        .collect();
+
+    b.iter(|| {
+        for mol in &mols {
+            test::black_box(mol.clone());
+        }
+    });
+}
diff --git a/rdkit-sys/Cargo.toml b/rdkit-sys/Cargo.toml
index 722c75a..553f31b 100644
--- a/rdkit-sys/Cargo.toml
+++ b/rdkit-sys/Cargo.toml
@@ -2,7 +2,7 @@
 name = "rdkit-sys"
 authors = ["Xavier Lange (xrlange@gmail.com)", "chrissly31415"]
 version = "0.4.12"
-edition = "2021"
+edition = "2024"
 license = "MIT"
 description = "RDKit CFFI library builder and bindings"
 repository = "https://github.com/rdkit-rs/rdkit/tree/main/rdkit-sys"
@@ -14,9 +14,9 @@ exclude = ["rdkit-*", "*.tar.gz", "examples/"]
 cxx = "1.0.109"
 
 [build-dependencies]
-env_logger = "0.10.0"
+env_logger = "0.11"
 cxx-build = "1.0.109"
-which = "4.4.2"
+which = "8"
 
 [features]
 default = []
diff --git a/rdkit-sys/build.rs b/rdkit-sys/build.rs
index 782861d..d5ba17e 100644
--- a/rdkit-sys/build.rs
+++ b/rdkit-sys/build.rs
@@ -1,4 +1,4 @@
-const CPP_VERSION_FLAG: &str = "-std=c++17";
+const CPP_VERSION_FLAG: &str = "-std=c++20";
 
 fn main() {
     if std::env::var("DOCS_RS").is_ok() {
diff --git a/rdkit-sys/rustfmt.toml b/rdkit-sys/rustfmt.toml
index 7de3b73..6edb4d8 100644
--- a/rdkit-sys/rustfmt.toml
+++ b/rdkit-sys/rustfmt.toml
@@ -48,8 +48,8 @@ trailing_comma = "Vertical"
 match_block_trailing_comma = false
 blank_lines_upper_bound = 1
 blank_lines_lower_bound = 0
-edition = "2021"
-version = "One"
+edition = "2024"
+style_edition = "2024"
 inline_attribute_width = 0
 format_generated_files = true
 merge_derives = true
diff --git a/rdkit-sys/src/bridge/fingerprint.rs b/rdkit-sys/src/bridge/fingerprint.rs
index 44eb48c..4951740 100644
--- a/rdkit-sys/src/bridge/fingerprint.rs
+++ b/rdkit-sys/src/bridge/fingerprint.rs
@@ -17,5 +17,24 @@ pub mod ffi {
         pub fn explicit_bit_vect_to_u64_vec(
             bitvect: &SharedPtr<ExplicitBitVect>,
         ) -> UniquePtr<CxxVector<u64>>;
+
+        // Configurable fingerprints
+        pub fn morgan_fingerprint_mol_with_params(
+            mol: &SharedPtr<ROMol>,
+            radius: u32,
+            n_bits: u32,
+        ) -> SharedPtr<ExplicitBitVect>;
+        pub fn rdk_fingerprint_mol_with_params(
+            mol: &SharedPtr<ROMol>,
+            min_path: u32,
+            max_path: u32,
+            fp_size: u32,
+        ) -> SharedPtr<ExplicitBitVect>;
+        pub fn pattern_fingerprint_mol_with_params(
+            mol: &SharedPtr<ROMol>,
+            fp_size: u32,
+        ) -> SharedPtr<ExplicitBitVect>;
+        pub fn maccs_fingerprint_mol(mol: &SharedPtr<ROMol>) -> SharedPtr<ExplicitBitVect>;
+        pub fn explicit_bit_vect_num_bits(bitvect: &SharedPtr<ExplicitBitVect>) -> u32;
     }
 }
diff --git a/rdkit-sys/src/bridge/mod.rs b/rdkit-sys/src/bridge/mod.rs
index 1593316..e020a81 100644
--- a/rdkit-sys/src/bridge/mod.rs
+++ b/rdkit-sys/src/bridge/mod.rs
@@ -11,7 +11,7 @@ mod mol_standardize;
 pub use mol_standardize::ffi as mol_standardize_ffi;
 
 mod periodic_table;
-pub use periodic_table::{ffi as periodic_table_ffi, PeriodicTableOps};
+pub use periodic_table::{PeriodicTableOps, ffi as periodic_table_ffi};
 
 mod ro_mol;
 pub use ro_mol::ffi as ro_mol_ffi;
diff --git a/rdkit-sys/src/bridge/periodic_table.rs b/rdkit-sys/src/bridge/periodic_table.rs
index b08b1fb..21e0dfa 100644
--- a/rdkit-sys/src/bridge/periodic_table.rs
+++ b/rdkit-sys/src/bridge/periodic_table.rs
@@ -43,7 +43,7 @@ pub trait PeriodicTableOps {
     fn getElementName(self, atomic_number: u32) -> String;
     fn getValenceList(self, atomic_number: u32) -> &'static CxxVector<i32>;
 }
-impl<'a> PeriodicTableOps for UniquePtr<PeriodicTable> {
+impl PeriodicTableOps for UniquePtr<PeriodicTable> {
     fn getElementSymbol(self, atomic_number: u32) -> String {
         ffi::getElementSymbol(atomic_number)
     }
diff --git a/rdkit-sys/src/bridge/ro_mol.rs b/rdkit-sys/src/bridge/ro_mol.rs
index fffa0e7..2e5ac6e 100644
--- a/rdkit-sys/src/bridge/ro_mol.rs
+++ b/rdkit-sys/src/bridge/ro_mol.rs
@@ -59,6 +59,7 @@ pub mod ffi {
 
         pub fn get_num_atoms(mol: &SharedPtr<ROMol>, onlyExplicit: bool) -> u32;
         pub fn get_atom_with_idx(mol: &mut SharedPtr<ROMol>, idx: u32) -> Pin<&mut Atom>;
+        pub fn get_atom_with_idx_const(mol: &SharedPtr<ROMol>, idx: u32) -> Pin<&Atom>;
         pub fn get_symbol(atom: Pin<&Atom>) -> String;
         pub fn get_is_aromatic(atom: Pin<&Atom>) -> bool;
         pub fn get_atomic_num(atom: Pin<&Atom>) -> i32;
diff --git a/rdkit-sys/tests/test_atoms.rs b/rdkit-sys/tests/test_atoms.rs
index f5d9d5c..fe12146 100644
--- a/rdkit-sys/tests/test_atoms.rs
+++ b/rdkit-sys/tests/test_atoms.rs
@@ -17,7 +17,9 @@ fn test_atoms() {
 
     assert_eq!(
         &atoms,
-        &["C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C"]
+        &[
+            "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C", "C"
+        ]
     );
 
     let mut atom = rdkit_sys::ro_mol_ffi::get_atom_with_idx(&mut romol, 2);
diff --git a/rdkit-sys/tests/test_ro_mol.rs b/rdkit-sys/tests/test_ro_mol.rs
index 50b6bc8..db77dc7 100644
--- a/rdkit-sys/tests/test_ro_mol.rs
+++ b/rdkit-sys/tests/test_ro_mol.rs
@@ -69,7 +69,10 @@ fn mol_to_molblock_test() {
     cxx::let_cxx_string!(smiles = "CC");
     let romol = rdkit_sys::ro_mol_ffi::smiles_to_mol(&smiles).unwrap();
     let molblock = rdkit_sys::ro_mol_ffi::mol_to_molblock(&romol);
-    assert_eq!(molblock, "\n     RDKit          2D\n\n  2  1  0  0  0  0  0  0  0  0999 V2000\n    0.0000    0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0\n    1.2990    0.7500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0\n  1  2  1  0\nM  END\n");
+    assert_eq!(
+        molblock,
+        "\n     RDKit          2D\n\n  2  1  0  0  0  0  0  0  0  0999 V2000\n    0.0000    0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0\n    1.2990    0.7500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0\n  1  2  1  0\nM  END\n"
+    );
 }
 
 #[test]
diff --git a/rdkit-sys/tests/test_rw_mol.rs b/rdkit-sys/tests/test_rw_mol.rs
index f31ee43..c42dfeb 100644
--- a/rdkit-sys/tests/test_rw_mol.rs
+++ b/rdkit-sys/tests/test_rw_mol.rs
@@ -1,4 +1,4 @@
-use cxx::{let_cxx_string, SharedPtr};
+use cxx::{SharedPtr, let_cxx_string};
 use rdkit_sys::{ro_mol_ffi::ROMol, rw_mol_ffi::RWMol};
 
 #[test]
@@ -191,7 +191,10 @@ CC(=O)OC(CC(=O)[O-])C[N+](C)(C)C
     let ro_mol = unsafe { std::mem::transmute::<SharedPtr<RWMol>, SharedPtr<ROMol>>(rw_mol) };
 
     let smiles = rdkit_sys::ro_mol_ffi::mol_to_smiles(&ro_mol);
-    assert_eq!("[H]C([H])([H])C(=O)OC([H])(C([H])([H])C(=O)[O-])C([H])([H])[N+](C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H]", &smiles);
+    assert_eq!(
+        "[H]C([H])([H])C(=O)OC([H])(C([H])([H])C(=O)[O-])C([H])([H])[N+](C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H]",
+        &smiles
+    );
 }
 
 #[test]
diff --git a/rdkit-sys/wrapper/include/fingerprint.h b/rdkit-sys/wrapper/include/fingerprint.h
index f1fe3e7..2c37b49 100644
--- a/rdkit-sys/wrapper/include/fingerprint.h
+++ b/rdkit-sys/wrapper/include/fingerprint.h
@@ -11,4 +11,15 @@ std::shared_ptr<ExplicitBitVect> copy_explicit_bit_vect(const std::shared_ptr<Ex
 unsigned int get_num_on_bits(const std::shared_ptr<ExplicitBitVect> &bitvect);
 
 std::unique_ptr<std::vector<uint64_t>> explicit_bit_vect_to_u64_vec(const std::shared_ptr<ExplicitBitVect> &bitvect);
+
+// Configurable fingerprints
+std::shared_ptr<ExplicitBitVect> morgan_fingerprint_mol_with_params(const std::shared_ptr<ROMol> &mol,
+                                                                    unsigned int radius, unsigned int n_bits);
+std::shared_ptr<ExplicitBitVect> rdk_fingerprint_mol_with_params(const std::shared_ptr<ROMol> &mol,
+                                                                 unsigned int min_path, unsigned int max_path,
+                                                                 unsigned int fp_size);
+std::shared_ptr<ExplicitBitVect> pattern_fingerprint_mol_with_params(const std::shared_ptr<ROMol> &mol,
+                                                                     unsigned int fp_size);
+std::shared_ptr<ExplicitBitVect> maccs_fingerprint_mol(const std::shared_ptr<ROMol> &mol);
+unsigned int explicit_bit_vect_num_bits(const std::shared_ptr<ExplicitBitVect> &bitvect);
 } // namespace RDKit
\ No newline at end of file
diff --git a/rdkit-sys/wrapper/include/ro_mol.h b/rdkit-sys/wrapper/include/ro_mol.h
index 6cbe18d..6fbe6ea 100644
--- a/rdkit-sys/wrapper/include/ro_mol.h
+++ b/rdkit-sys/wrapper/include/ro_mol.h
@@ -29,6 +29,8 @@ unsigned int atom_sanitize_exception_get_atom_idx(const MolSanitizeExceptionUniq
 
 unsigned int get_num_atoms(const std::shared_ptr<ROMol> &mol, bool only_explicit);
 Atom &get_atom_with_idx(std::shared_ptr<ROMol> &mol, unsigned int idx);
+const Atom &get_atom_with_idx_const(const std::shared_ptr<ROMol> &mol,
+                                    unsigned int idx);
 rust::String get_symbol(const Atom &atom);
 bool get_is_aromatic(const Atom &atom);
 int get_atomic_num(const Atom &atom);
diff --git a/rdkit-sys/wrapper/src/fingerprint.cc b/rdkit-sys/wrapper/src/fingerprint.cc
index 83c939f..a98541e 100644
--- a/rdkit-sys/wrapper/src/fingerprint.cc
+++ b/rdkit-sys/wrapper/src/fingerprint.cc
@@ -1,6 +1,7 @@
 #include "rust/cxx.h"
 #include <DataStructs/ExplicitBitVect.h>
 #include <GraphMol/Fingerprints/Fingerprints.h>
+#include <GraphMol/Fingerprints/MACCS.h>
 #include <GraphMol/Fingerprints/MorganFingerprints.h>
 
 namespace RDKit {
@@ -28,4 +29,28 @@ std::unique_ptr<std::vector<uint64_t>> explicit_bit_vect_to_u64_vec(const std::s
 	std::vector<uint64_t> *bytes_heap = new std::vector<uint64_t>(bytes);
 	return std::unique_ptr<std::vector<uint64_t>>(bytes_heap);
 }
+
+std::shared_ptr<ExplicitBitVect> morgan_fingerprint_mol_with_params(const std::shared_ptr<ROMol> &mol,
+                                                                    unsigned int radius, unsigned int n_bits) {
+	return std::shared_ptr<ExplicitBitVect>(MorganFingerprints::getFingerprintAsBitVect(*mol, radius, n_bits));
+}
+
+std::shared_ptr<ExplicitBitVect> rdk_fingerprint_mol_with_params(const std::shared_ptr<ROMol> &mol,
+                                                                 unsigned int min_path, unsigned int max_path,
+                                                                 unsigned int fp_size) {
+	return std::shared_ptr<ExplicitBitVect>(RDKFingerprintMol(*mol, min_path, max_path, fp_size));
+}
+
+std::shared_ptr<ExplicitBitVect> pattern_fingerprint_mol_with_params(const std::shared_ptr<ROMol> &mol,
+                                                                     unsigned int fp_size) {
+	return std::shared_ptr<ExplicitBitVect>(PatternFingerprintMol(*mol, fp_size));
+}
+
+std::shared_ptr<ExplicitBitVect> maccs_fingerprint_mol(const std::shared_ptr<ROMol> &mol) {
+	return std::shared_ptr<ExplicitBitVect>(MACCSFingerprints::getFingerprintAsBitVect(*mol));
+}
+
+unsigned int explicit_bit_vect_num_bits(const std::shared_ptr<ExplicitBitVect> &bitvect) {
+	return bitvect->getNumBits();
+}
 } // namespace RDKit
\ No newline at end of file
diff --git a/rdkit-sys/wrapper/src/ro_mol.cc b/rdkit-sys/wrapper/src/ro_mol.cc
index 2442a0b..d3ee865 100644
--- a/rdkit-sys/wrapper/src/ro_mol.cc
+++ b/rdkit-sys/wrapper/src/ro_mol.cc
@@ -69,6 +69,10 @@ unsigned int get_num_atoms(const std::shared_ptr<ROMol> &mol, bool only_explicit
 
 Atom &get_atom_with_idx(std::shared_ptr<ROMol> &mol, unsigned int idx) { return *mol->getAtomWithIdx(idx); }
 
+const Atom &get_atom_with_idx_const(const std::shared_ptr<ROMol> &mol, unsigned int idx) {
+	return *mol->getAtomWithIdx(idx);
+}
+
 rust::String get_symbol(const Atom &atom) { return atom.getSymbol(); }
 
 bool get_is_aromatic(const Atom &atom) { return atom.getIsAromatic(); }
diff --git a/rustfmt.toml b/rustfmt.toml
index 7de3b73..6edb4d8 100644
--- a/rustfmt.toml
+++ b/rustfmt.toml
@@ -48,8 +48,8 @@ trailing_comma = "Vertical"
 match_block_trailing_comma = false
 blank_lines_upper_bound = 1
 blank_lines_lower_bound = 0
-edition = "2021"
-version = "One"
+edition = "2024"
+style_edition = "2024"
 inline_attribute_width = 0
 format_generated_files = true
 merge_derives = true
diff --git a/src/descriptors.rs b/src/descriptors.rs
index a3272c9..a6511d6 100644
--- a/src/descriptors.rs
+++ b/src/descriptors.rs
@@ -25,7 +25,7 @@ impl Properties {
         let names = rdkit_sys::descriptors_ffi::get_property_names(&self.ptr);
         let computed = rdkit_sys::descriptors_ffi::compute_properties(&self.ptr, &ro_mol.ptr);
 
-        assert!(names.len() != 0);
+        assert!(!names.is_empty());
         assert!(computed.len() == names.len());
 
         names
diff --git a/src/fingerprint.rs b/src/fingerprint.rs
index e2bdc46..41ccb29 100644
--- a/src/fingerprint.rs
+++ b/src/fingerprint.rs
@@ -6,9 +6,11 @@ pub struct Fingerprint(pub BitVec<u8, bitvec::order::Lsb0>);
 
 impl Fingerprint {
     pub fn new(ptr: SharedPtr<rdkit_sys::fingerprint_ffi::ExplicitBitVect>) -> Self {
+        let num_bits = rdkit_sys::fingerprint_ffi::explicit_bit_vect_num_bits(&ptr) as usize;
         let unique_ptr_bytes = rdkit_sys::fingerprint_ffi::explicit_bit_vect_to_u64_vec(&ptr);
         let rdkit_fingerprint_bytes: Vec<u64> = unique_ptr_bytes.into_iter().copied().collect();
         let mut bitvec_u64 = bitvec::vec::BitVec::<u64, Lsb0>::from_vec(rdkit_fingerprint_bytes);
+        bitvec_u64.truncate(num_bits);
 
         let mut idiomatic_bitvec_u8 = bitvec::vec::BitVec::<u8, Lsb0>::new();
         idiomatic_bitvec_u8.append(&mut bitvec_u64);
@@ -16,6 +18,14 @@ impl Fingerprint {
         Fingerprint(idiomatic_bitvec_u8)
     }
 
+    pub fn len(&self) -> usize {
+        self.0.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
     pub fn tanimoto_distance(&self, other: &Fingerprint) -> f32 {
         let and = self.0.clone() & &other.0;
         let or = self.0.clone() | &other.0;
diff --git a/src/graphmol/atom_ref.rs b/src/graphmol/atom_ref.rs
new file mode 100644
index 0000000..c6422d7
--- /dev/null
+++ b/src/graphmol/atom_ref.rs
@@ -0,0 +1,88 @@
+use std::{fmt::Formatter, pin::Pin};
+
+use rdkit_sys::ro_mol_ffi;
+pub use rdkit_sys::ro_mol_ffi::HybridizationType;
+
+/// Read-only view of an atom within a molecule.
+///
+/// Unlike [`Atom`](crate::Atom), this borrows the parent molecule immutably
+/// (`&self`), so multiple `AtomRef`s can coexist and no clone is needed.
+pub struct AtomRef<'a> {
+    ptr: Pin<&'a ro_mol_ffi::Atom>,
+}
+
+impl<'a> std::fmt::Display for AtomRef<'a> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let symbol = self.symbol();
+        f.write_str(&symbol)
+    }
+}
+
+impl<'a> std::fmt::Debug for AtomRef<'a> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        let symbol = self.symbol();
+        f.write_str(&symbol)
+    }
+}
+
+impl<'a> AtomRef<'a> {
+    pub fn from_ptr(ptr: Pin<&'a ro_mol_ffi::Atom>) -> Self {
+        Self { ptr }
+    }
+
+    pub fn symbol(&self) -> String {
+        ro_mol_ffi::get_symbol(self.ptr)
+    }
+
+    pub fn get_is_aromatic(&self) -> bool {
+        ro_mol_ffi::get_is_aromatic(self.ptr)
+    }
+
+    pub fn get_atomic_num(&self) -> i32 {
+        ro_mol_ffi::get_atomic_num(self.ptr)
+    }
+
+    pub fn get_formal_charge(&self) -> i32 {
+        ro_mol_ffi::get_formal_charge(self.ptr)
+    }
+
+    pub fn get_total_num_hs(&self) -> u32 {
+        ro_mol_ffi::get_total_num_hs(self.ptr)
+    }
+
+    pub fn get_total_valence(&self) -> u32 {
+        ro_mol_ffi::get_total_valence(self.ptr)
+    }
+
+    pub fn get_hybridization_type(&self) -> HybridizationType {
+        ro_mol_ffi::atom_get_hybridization(self.ptr)
+    }
+
+    pub fn get_num_radical_electrons(&self) -> u32 {
+        ro_mol_ffi::get_num_radical_electrons(self.ptr)
+    }
+
+    pub fn get_degree(&self) -> u32 {
+        ro_mol_ffi::get_degree(self.ptr)
+    }
+
+    pub fn get_int_prop(&self, key: &str) -> Result<i32, cxx::Exception> {
+        cxx::let_cxx_string!(key = key);
+        ro_mol_ffi::get_int_prop(self.ptr, &key)
+    }
+
+    pub fn get_float_prop(&self, key: &str) -> Result<f64, cxx::Exception> {
+        cxx::let_cxx_string!(key = key);
+        ro_mol_ffi::get_float_prop(self.ptr, &key)
+    }
+
+    pub fn get_bool_prop(&self, key: &str) -> Result<bool, cxx::Exception> {
+        cxx::let_cxx_string!(key = key);
+        ro_mol_ffi::get_bool_prop(self.ptr, &key)
+    }
+
+    pub fn get_prop(&self, key: &str) -> Result<String, cxx::Exception> {
+        cxx::let_cxx_string!(key = key);
+        ro_mol_ffi::get_prop(self.ptr, &key)
+    }
+}
diff --git a/src/graphmol/mod.rs b/src/graphmol/mod.rs
index f23a721..1b1309b 100644
--- a/src/graphmol/mod.rs
+++ b/src/graphmol/mod.rs
@@ -1,6 +1,9 @@
 mod atom;
 pub use atom::*;
 
+mod atom_ref;
+pub use atom_ref::*;
+
 mod mol_ops;
 pub use mol_ops::*;
 
diff --git a/src/graphmol/ro_mol.rs b/src/graphmol/ro_mol.rs
index bcdd30c..5b0bb5b 100644
--- a/src/graphmol/ro_mol.rs
+++ b/src/graphmol/ro_mol.rs
@@ -3,7 +3,7 @@ use std::fmt::{Debug, Formatter};
 use cxx::let_cxx_string;
 use rdkit_sys::*;
 
-use crate::{Atom, Fingerprint, RWMol};
+use crate::{Atom, AtomRef, Fingerprint, RWMol};
 
 pub struct ROMol {
     pub(crate) ptr: cxx::SharedPtr<ro_mol_ffi::ROMol>,
@@ -85,15 +85,51 @@ impl ROMol {
         Fingerprint::new(ptr)
     }
 
+    pub fn morgan_fingerprint_with_params(&self, radius: u32, n_bits: u32) -> Fingerprint {
+        let ptr = fingerprint_ffi::morgan_fingerprint_mol_with_params(&self.ptr, radius, n_bits);
+        Fingerprint::new(ptr)
+    }
+
+    pub fn rdk_fingerprint_with_params(
+        &self,
+        min_path: u32,
+        max_path: u32,
+        fp_size: u32,
+    ) -> Fingerprint {
+        let ptr = fingerprint_ffi::rdk_fingerprint_mol_with_params(
+            &self.ptr, min_path, max_path, fp_size,
+        );
+        Fingerprint::new(ptr)
+    }
+
+    pub fn pattern_fingerprint_with_params(&self, fp_size: u32) -> Fingerprint {
+        let ptr = fingerprint_ffi::pattern_fingerprint_mol_with_params(&self.ptr, fp_size);
+        Fingerprint::new(ptr)
+    }
+
+    pub fn maccs_fingerprint(&self) -> Fingerprint {
+        let ptr = fingerprint_ffi::maccs_fingerprint_mol(&self.ptr);
+        Fingerprint::new(ptr)
+    }
+
     pub fn num_atoms(&self, only_explicit: bool) -> u32 {
         ro_mol_ffi::get_num_atoms(&self.ptr, only_explicit)
     }
 
-    pub fn atom_with_idx(&mut self, idx: u32) -> Atom {
+    pub fn atom_with_idx(&mut self, idx: u32) -> Atom<'_> {
         let ptr = ro_mol_ffi::get_atom_with_idx(&mut self.ptr, idx);
         Atom::from_ptr(ptr)
     }
 
+    /// Returns a read-only reference to the atom at `idx`.
+    ///
+    /// Unlike [`atom_with_idx`](Self::atom_with_idx), this takes `&self`,
+    /// so no mutable borrow (or clone) is needed for read-only access.
+    pub fn atom_ref(&self, idx: u32) -> AtomRef<'_> {
+        let ptr = ro_mol_ffi::get_atom_with_idx_const(&self.ptr, idx);
+        AtomRef::from_ptr(ptr)
+    }
+
     pub fn update_property_cache(&mut self, strict: bool) {
         ro_mol_ffi::ro_mol_update_property_cache(&mut self.ptr, strict)
     }
diff --git a/src/graphmol/rw_mol.rs b/src/graphmol/rw_mol.rs
index 6467120..b640d50 100644
--- a/src/graphmol/rw_mol.rs
+++ b/src/graphmol/rw_mol.rs
@@ -1,6 +1,6 @@
 use std::fmt::Formatter;
 
-use cxx::{let_cxx_string, SharedPtr};
+use cxx::{SharedPtr, let_cxx_string};
 use rdkit_sys::*;
 
 use crate::ROMol;
diff --git a/src/periodic_table.rs b/src/periodic_table.rs
index 60fc473..cf66658 100644
--- a/src/periodic_table.rs
+++ b/src/periodic_table.rs
@@ -1,4 +1,4 @@
-use cxx::{let_cxx_string, CxxVector};
+use cxx::{CxxVector, let_cxx_string};
 use rdkit_sys::PeriodicTableOps;
 
 pub struct PeriodicTable {}
@@ -18,8 +18,8 @@ impl PeriodicTable {
     /// * `atom` - The symbol of the element
     pub fn get_most_common_isotope_mass(atom: &str) -> f64 {
         let_cxx_string!(atom_cxx_string = atom);
-        rdkit_sys::periodic_table_ffi::get_periodic_table()
-            .getMostCommonIsotopeMass(&atom_cxx_string)
+        let pt = rdkit_sys::periodic_table_ffi::get_periodic_table();
+        pt.getMostCommonIsotopeMass(&atom_cxx_string)
     }
 
     /// Returns the atomic weight of the atom
@@ -32,7 +32,8 @@ impl PeriodicTable {
     /// * `atom` - The symbol of the element
     pub fn get_atomic_number(atom: &str) -> i32 {
         let_cxx_string!(atom_cxx_string = atom);
-        rdkit_sys::periodic_table_ffi::get_periodic_table().getAtomicNumber(&atom_cxx_string)
+        let pt = rdkit_sys::periodic_table_ffi::get_periodic_table();
+        pt.getAtomicNumber(&atom_cxx_string)
     }
 
     /// Returns the symbol of the element
diff --git a/tests/test_atom_ref.rs b/tests/test_atom_ref.rs
new file mode 100644
index 0000000..55c80e9
--- /dev/null
+++ b/tests/test_atom_ref.rs
@@ -0,0 +1,81 @@
+/// Verify AtomRef returns identical results to Atom for all read-only methods.
+#[test]
+fn test_atom_ref_parity() {
+    let mut romol = rdkit::ROMol::from_smiles("[NH4+]").unwrap();
+
+    // Read via mutable Atom
+    let atom = romol.atom_with_idx(0);
+    let symbol = atom.symbol();
+    let is_aromatic = atom.get_is_aromatic();
+    let atomic_num = atom.get_atomic_num();
+    let hybridization = atom.get_hybridization_type();
+    let formal_charge = atom.get_formal_charge();
+    let total_num_hs = atom.get_total_num_hs();
+    let total_valence = atom.get_total_valence();
+    let num_radical_electrons = atom.get_num_radical_electrons();
+    let degree = atom.get_degree();
+
+    // Read via immutable AtomRef — must match exactly
+    let atom_ref = romol.atom_ref(0);
+    assert_eq!(atom_ref.symbol(), symbol);
+    assert_eq!(atom_ref.get_is_aromatic(), is_aromatic);
+    assert_eq!(atom_ref.get_atomic_num(), atomic_num);
+    assert_eq!(atom_ref.get_hybridization_type(), hybridization);
+    assert_eq!(atom_ref.get_formal_charge(), formal_charge);
+    assert_eq!(atom_ref.get_total_num_hs(), total_num_hs);
+    assert_eq!(atom_ref.get_total_valence(), total_valence);
+    assert_eq!(atom_ref.get_num_radical_electrons(), num_radical_electrons);
+    assert_eq!(atom_ref.get_degree(), degree);
+}
+
+/// Verify AtomRef property getters work.
+#[test]
+fn test_atom_ref_properties() {
+    let mut romol = rdkit::ROMol::from_smiles("CC").unwrap();
+
+    // Set properties via mutable Atom
+    {
+        let mut carbon = romol.atom_with_idx(0);
+        carbon.set_prop("int_key", 42);
+        carbon.set_prop("float_key", 3.14);
+        carbon.set_prop("bool_key", true);
+        carbon.set_prop("str_key", "hello");
+    }
+
+    // Read back via immutable AtomRef
+    let atom_ref = romol.atom_ref(0);
+    assert_eq!(atom_ref.get_int_prop("int_key").unwrap(), 42);
+    assert_eq!(atom_ref.get_float_prop("float_key").unwrap(), 3.14);
+    assert_eq!(atom_ref.get_bool_prop("bool_key").unwrap(), true);
+    assert_eq!(atom_ref.get_prop("str_key").unwrap(), "hello");
+}
+
+/// Verify multiple AtomRefs can coexist (no &mut self needed).
+#[test]
+fn test_atom_ref_no_clone_needed() {
+    let romol = rdkit::ROMol::from_smiles("CCO").unwrap();
+
+    // This would not compile with atom_with_idx since it needs &mut self.
+    // With atom_ref, we can hold multiple references simultaneously.
+    let c1 = romol.atom_ref(0);
+    let c2 = romol.atom_ref(1);
+    let o = romol.atom_ref(2);
+
+    assert_eq!(c1.symbol(), "C");
+    assert_eq!(c2.symbol(), "C");
+    assert_eq!(o.symbol(), "O");
+}
+
+/// Verify AtomRef works across all atoms in a molecule.
+#[test]
+fn test_atom_ref_iteration() {
+    let romol = rdkit::ROMol::from_smiles("c1ccccc1").unwrap();
+    let n = romol.num_atoms(true);
+    assert_eq!(n, 6);
+
+    for i in 0..n {
+        let atom = romol.atom_ref(i);
+        assert_eq!(atom.symbol(), "C");
+        assert!(atom.get_is_aromatic());
+    }
+}
diff --git a/tests/test_fingerprint_params.rs b/tests/test_fingerprint_params.rs
new file mode 100644
index 0000000..85fdd80
--- /dev/null
+++ b/tests/test_fingerprint_params.rs
@@ -0,0 +1,46 @@
+use rdkit::ROMol;
+
+#[test]
+fn test_morgan_different_radius() {
+    let mol = ROMol::from_smiles("c1ccccc1CC").unwrap();
+    let fp_r2 = mol.morgan_fingerprint_with_params(2, 2048);
+    let fp_r3 = mol.morgan_fingerprint_with_params(3, 2048);
+    assert_ne!(fp_r2.0, fp_r3.0);
+    assert_eq!(fp_r2.len(), 2048);
+}
+
+#[test]
+fn test_morgan_custom_nbits() {
+    let mol = ROMol::from_smiles("c1ccccc1").unwrap();
+    let fp = mol.morgan_fingerprint_with_params(2, 1024);
+    assert_eq!(fp.len(), 1024);
+}
+
+#[test]
+fn test_rdk_fingerprint_with_params() {
+    let mol = ROMol::from_smiles("c1ccccc1CCCC").unwrap();
+    let fp = mol.rdk_fingerprint_with_params(1, 7, 1024);
+    assert_eq!(fp.len(), 1024);
+}
+
+#[test]
+fn test_pattern_fingerprint_with_params() {
+    let mol = ROMol::from_smiles("c1ccccc1").unwrap();
+    let fp = mol.pattern_fingerprint_with_params(1024);
+    assert_eq!(fp.len(), 1024);
+}
+
+#[test]
+fn test_maccs_fingerprint() {
+    let mol = ROMol::from_smiles("c1ccccc1").unwrap();
+    let fp = mol.maccs_fingerprint();
+    assert_eq!(fp.len(), 167);
+}
+
+#[test]
+fn test_fingerprint_len() {
+    let mol = ROMol::from_smiles("CC").unwrap();
+    let fp = mol.morgan_fingerprint();
+    assert!(!fp.is_empty());
+    assert_eq!(fp.len(), 2048);
+}
diff --git a/tests/test_graphmol.rs b/tests/test_graphmol.rs
index 64587f1..e167672 100644
--- a/tests/test_graphmol.rs
+++ b/tests/test_graphmol.rs
@@ -1,7 +1,7 @@
 use rdkit::{
-    detect_chemistry_problems, fragment_parent, substruct_match, CleanupParameters,
-    MolSanitizeException, ROMol, ROMolError, RWMol, SmilesParserParams, SubstructMatchParameters,
-    TautomerEnumerator, Uncharger,
+    CleanupParameters, MolSanitizeException, ROMol, ROMolError, RWMol, SmilesParserParams,
+    SubstructMatchParameters, TautomerEnumerator, Uncharger, detect_chemistry_problems,
+    fragment_parent, substruct_match,
 };
 
 #[test]
@@ -15,7 +15,10 @@ fn test_neutralize() {
     let romol = ROMol::from_smiles(smiles).unwrap();
     let uncharger = Uncharger::new(false);
     let uncharged_mol = uncharger.uncharge(&romol);
-    assert_eq!("CCOC(=O)C(C)(C)Oc1ccc(Cl)cc1.CO.Nc1nc2ncc(CNc3ccc(C(=O)N[C@@H](CCC(=O)O)C(=O)O)cc3)nc2c(=O)[nH]1", uncharged_mol.as_smiles());
+    assert_eq!(
+        "CCOC(=O)C(C)(C)Oc1ccc(Cl)cc1.CO.Nc1nc2ncc(CNc3ccc(C(=O)N[C@@H](CCC(=O)O)C(=O)O)cc3)nc2c(=O)[nH]1",
+        uncharged_mol.as_smiles()
+    );
 }
 
 #[test]
@@ -29,7 +32,10 @@ fn test_fragment_parent() {
         "Nc1nc2ncc(CNc3ccc(C(=O)N[C@@H](CCC(=O)O)C(=O)O)cc3)nc2c(=O)[nH]1",
         parent_rwmol.as_smiles()
     );
-    assert_eq!("CCOC(=O)C(C)(C)Oc1ccc(Cl)cc1.CO.Nc1nc2ncc(CNc3ccc(C(=O)N[C@@H](CCC(=O)O)C(=O)O)cc3)nc2c(=O)[nH]1", rwmol.as_smiles());
+    assert_eq!(
+        "CCOC(=O)C(C)(C)Oc1ccc(Cl)cc1.CO.Nc1nc2ncc(CNc3ccc(C(=O)N[C@@H](CCC(=O)O)C(=O)O)cc3)nc2c(=O)[nH]1",
+        rwmol.as_smiles()
+    );
 }
 
 #[test]
@@ -271,7 +277,10 @@ CC(=O)OC(CC(=O)[O-])C[N+](C)(C)C
 "#;
 
     let rw_mol = RWMol::from_mol_block(mol_block, false, false, false).unwrap();
-    assert_eq!("[H]C([H])([H])C(=O)OC([H])(C([H])([H])C(=O)[O-])C([H])([H])[N+](C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H]", &rw_mol.as_smiles());
+    assert_eq!(
+        "[H]C([H])([H])C(=O)OC([H])(C([H])([H])C(=O)[O-])C([H])([H])[N+](C([H])([H])[H])(C([H])([H])[H])C([H])([H])[H]",
+        &rw_mol.as_smiles()
+    );
 }
 
 #[test]
@@ -326,5 +335,8 @@ fn mol_to_molblock_test() {
     let smiles = "CC";
     let romol = ROMol::from_smiles(&smiles).unwrap();
     let molblock = romol.to_molblock();
-    assert_eq!(molblock, "\n     RDKit          2D\n\n  2  1  0  0  0  0  0  0  0  0999 V2000\n    0.0000    0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0\n    1.2990    0.7500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0\n  1  2  1  0\nM  END\n");
+    assert_eq!(
+        molblock,
+        "\n     RDKit          2D\n\n  2  1  0  0  0  0  0  0  0  0999 V2000\n    0.0000    0.0000    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0\n    1.2990    0.7500    0.0000 C   0  0  0  0  0  0  0  0  0  0  0  0\n  1  2  1  0\nM  END\n"
+    );
 }
diff --git a/tests/test_mol_ops.rs b/tests/test_mol_ops.rs
index 42e4cb3..56dc92c 100644
--- a/tests/test_mol_ops.rs
+++ b/tests/test_mol_ops.rs
@@ -1,4 +1,4 @@
-use rdkit::{add_hs, clean_up, remove_hs, set_hybridization, ROMol, RemoveHsParameters};
+use rdkit::{ROMol, RemoveHsParameters, add_hs, clean_up, remove_hs, set_hybridization};
 
 #[test]
 fn test_remove_hs() {
diff --git a/tests/test_substruct.rs b/tests/test_substruct.rs
index 851e0bc..dbe2b7f 100644
--- a/tests/test_substruct.rs
+++ b/tests/test_substruct.rs
@@ -1,4 +1,4 @@
-use rdkit::{substruct_match, ROMol, SubstructMatchItem, SubstructMatchParameters};
+use rdkit::{ROMol, SubstructMatchItem, SubstructMatchParameters, substruct_match};
 
 #[test]
 fn test_substruct_match() {