diff --git a/src/scf/driver/scf_loop.cpp b/src/scf/driver/scf_loop.cpp
index f50a51d..b91a9f4 100644
--- a/src/scf/driver/scf_loop.cpp
+++ b/src/scf/driver/scf_loop.cpp
@@ -173,9 +173,9 @@ MODULE_RUN(SCFLoop) {
     tensor_t e_nuclear(0.0);
     if(has_nn) {
         const auto& V_nn       = *visitor.m_pv;
-        const auto n_lhs       = V_nn.lhs_particle().as_nuclei();
+        const auto n_lhs       = V_nn.get_lhs_particle().as_nuclei();
         const auto qs_lhs_view = n_lhs.charges();
-        const auto n_rhs       = V_nn.rhs_particle().as_nuclei();
+        const auto n_rhs       = V_nn.get_rhs_particle().as_nuclei();
         const auto qs_rhs_view = n_rhs.charges();
         simde::type::charges qs_lhs;
         simde::type::charges qs_rhs;
diff --git a/src/scf/fock_operator/fock_operator_common.hpp b/src/scf/fock_operator/fock_operator_common.hpp
index c8b338f..d3fd8c4 100644
--- a/src/scf/fock_operator/fock_operator_common.hpp
+++ b/src/scf/fock_operator/fock_operator_common.hpp
@@ -35,7 +35,7 @@ class FockOperatorCommon : public chemist::qm_operator::OperatorVisitor {
     }
 
     void run(const V_en_term& V_en) {
-        auto rhs     = V_en.rhs_particle().as_nuclei();
+        auto rhs     = V_en.get_rhs_particle().as_nuclei();
         using v_type = Coulomb<ElectronType, simde::type::nuclei>;
         auto v       = std::make_unique<v_type>(get_e_(V_en), rhs);
         m_pF_->emplace_back(1.0, std::move(v));
@@ -47,7 +47,7 @@ class FockOperatorCommon : public chemist::qm_operator::OperatorVisitor {
         if constexpr(std::is_same_v<ElectronType, simde::type::electron>) {
             return simde::type::electron{};
         } else {
-            return op.template at<0>();
+            return op.template get<0>();
         }
     }
 
diff --git a/src/scf/guess/core.cpp b/src/scf/guess/core.cpp
index e5f7ad2..8ff7587 100644
--- a/src/scf/guess/core.cpp
+++ b/src/scf/guess/core.cpp
@@ -38,15 +38,17 @@ using simde::type::tensor;
 struct NElectronCounter : public chemist::qm_operator::OperatorVisitor {
     NElectronCounter() : chemist::qm_operator::OperatorVisitor(false) {}
 
-    void run(const simde::type::T_e_type& T_e) { set_n(T_e.particle().size()); }
+    void run(const simde::type::T_e_type& T_e) {
+        set_n(T_e.get_particle().size());
+    }
 
     void run(const simde::type::V_en_type& V_en) {
-        set_n(V_en.lhs_particle().size());
+        set_n(V_en.get_lhs_particle().size());
     }
 
     void run(const simde::type::V_ee_type& V_ee) {
-        set_n(V_ee.lhs_particle().size());
-        set_n(V_ee.rhs_particle().size());
+        set_n(V_ee.get_lhs_particle().size());
+        set_n(V_ee.get_rhs_particle().size());
     }
 
     void set_n(unsigned int n) {
diff --git a/src/scf/guess/sad.cpp b/src/scf/guess/sad.cpp
index 9006355..c3f986b 100644
--- a/src/scf/guess/sad.cpp
+++ b/src/scf/guess/sad.cpp
@@ -39,15 +39,17 @@ using simde::type::tensor;
 struct NElectronCounter : public chemist::qm_operator::OperatorVisitor {
     NElectronCounter() : chemist::qm_operator::OperatorVisitor(false) {}
 
-    void run(const simde::type::T_e_type& T_e) { set_n(T_e.particle().size()); }
+    void run(const simde::type::T_e_type& T_e) {
+        set_n(T_e.get_particle().size());
+    }
 
     void run(const simde::type::V_en_type& V_en) {
-        set_n(V_en.lhs_particle().size());
+        set_n(V_en.get_lhs_particle().size());
     }
 
     void run(const simde::type::V_ee_type& V_ee) {
-        set_n(V_ee.lhs_particle().size());
-        set_n(V_ee.rhs_particle().size());
+        set_n(V_ee.get_lhs_particle().size());
+        set_n(V_ee.get_rhs_particle().size());
     }
 
     void set_n(unsigned int n) {
diff --git a/src/scf/matrix_builder/determinant_driver.cpp b/src/scf/matrix_builder/determinant_driver.cpp
index fd7c276..b3d3f6e 100644
--- a/src/scf/matrix_builder/determinant_driver.cpp
+++ b/src/scf/matrix_builder/determinant_driver.cpp
@@ -58,19 +58,19 @@ class DeterminantDispatcher : public chemist::qm_operator::OperatorVisitor {
 
     void run(const V_en_type& V_en) {
         simde::type::electron e;
-        simde::type::v_en_type v_en(e, V_en.rhs_particle().as_nuclei());
+        simde::type::v_en_type v_en(e, V_en.get_rhs_particle().as_nuclei());
         run_(v_en);
     }
 
     void run(const J_e_type& J_e) {
         simde::type::electron e;
-        simde::type::j_e_type j_e(e, J_e.rhs_particle());
+        simde::type::j_e_type j_e(e, J_e.get_rhs_particle());
         run_(j_e);
     }
 
     void run(const K_e_type& K_e) {
         simde::type::electron e;
-        simde::type::k_e_type k_e(e, K_e.rhs_particle());
+        simde::type::k_e_type k_e(e, K_e.get_rhs_particle());
         run_(k_e);
     }
 
diff --git a/src/scf/xc/gauxc/snlink.cpp b/src/scf/xc/gauxc/snlink.cpp
index 0ca2863..f7a2707 100644
--- a/src/scf/xc/gauxc/snlink.cpp
+++ b/src/scf/xc/gauxc/snlink.cpp
@@ -37,7 +37,7 @@ MODULE_CTOR(snLinK) {
 MODULE_RUN(snLinK) {
     const auto&& [braket] = k_type::unwrap_inputs(inputs);
     const auto& bra       = braket.bra();
-    const auto& P         = braket.op().rhs_particle();
+    const auto& P         = braket.op().get_rhs_particle();
     const auto& ket       = braket.ket();
 
     if(bra != ket || P.basis_set() != bra)
diff --git a/src/scf/xc/gauxc/xc_energy.cpp b/src/scf/xc/gauxc/xc_energy.cpp
index f089a76..9c0fed5 100644
--- a/src/scf/xc/gauxc/xc_energy.cpp
+++ b/src/scf/xc/gauxc/xc_energy.cpp
@@ -41,8 +41,8 @@ MODULE_RUN(XCEnergy) {
     if(bra_wf != ket_wf)
         throw std::runtime_error("Expected the same basis set");
 
-    const auto func = xc_op.functional_name();
-    const auto& P   = xc_op.rhs_particle();
+    const auto func = xc_op.get_functional_name();
+    const auto& P   = xc_op.get_rhs_particle();
     const auto& aos = P.basis_set().ao_basis_set();
 
     auto& driver           = submods.at("XC Driver");
diff --git a/src/scf/xc/gauxc/xc_potential.cpp b/src/scf/xc/gauxc/xc_potential.cpp
index 8e8d64d..8086b16 100644
--- a/src/scf/xc/gauxc/xc_potential.cpp
+++ b/src/scf/xc/gauxc/xc_potential.cpp
@@ -43,8 +43,8 @@ MODULE_RUN(XCPotential) {
     if(bra_aos != ket_aos)
         throw std::runtime_error("Expected the same basis set!");
 
-    const auto func = xc_op.functional_name();
-    const auto& P   = xc_op.rhs_particle();
+    const auto func = xc_op.get_functional_name();
+    const auto& P   = xc_op.get_rhs_particle();
     const auto& aos = bra_aos.ao_basis_set();
 
     auto& driver           = submods.at("XC Driver");
diff --git a/src/scf/xc/libxc/libxc_energy.cpp b/src/scf/xc/libxc/libxc_energy.cpp
index 4a1e4c9..2b3ddb5 100644
--- a/src/scf/xc/libxc/libxc_energy.cpp
+++ b/src/scf/xc/libxc/libxc_energy.cpp
@@ -51,8 +51,8 @@ MODULE_RUN(LibXCEnergy) {
     if(bra_wf != ket_wf)
         throw std::runtime_error("Expected the same basis set");
 
-    const auto func_name = xc_op.functional_name();
-    const auto& P        = xc_op.rhs_particle();
+    const auto func_name = xc_op.get_functional_name();
+    const auto& P        = xc_op.get_rhs_particle();
     const auto& aos      = P.basis_set().ao_basis_set();
 
     // Molecule from AOs
diff --git a/src/scf/xc/libxc/libxc_potential.cpp b/src/scf/xc/libxc/libxc_potential.cpp
index df72d4f..7ab43f6 100644
--- a/src/scf/xc/libxc/libxc_potential.cpp
+++ b/src/scf/xc/libxc/libxc_potential.cpp
@@ -48,8 +48,8 @@ MODULE_RUN(LibXCPotential) {
     if(bra_aos != ket_aos)
         throw std::runtime_error("Expected the same basis set!");
 
-    const auto func = xc_op.functional_name();
-    const auto& P   = xc_op.rhs_particle();
+    const auto func = xc_op.get_functional_name();
+    const auto& P   = xc_op.get_rhs_particle();
     const auto& aos = bra_aos.ao_basis_set();
 
     // Get grid