diff --git a/src/TiledArray/math/linalg/basic.h b/src/TiledArray/math/linalg/basic.h
index 2045c8a82c..e64b24af5a 100644
--- a/src/TiledArray/math/linalg/basic.h
+++ b/src/TiledArray/math/linalg/basic.h
@@ -155,6 +155,17 @@ inline void vec_multiply(
   a1.array() *= a2.array();
 }
 
+template <typename Derived>
+inline auto clone(const Eigen::MatrixBase<Derived>& a) {
+  return a.eval();
+}
+
+template <typename XprType1, int BlockRows1, int BlockCols1, bool InnerPanel1>
+inline auto clone(
+    const Eigen::Block<XprType1, BlockRows1, BlockCols1, InnerPanel1>& a) {
+  return a.eval();
+}
+
 template <typename Derived, typename S>
 inline void scale(Eigen::MatrixBase<Derived>& a, S scaling_factor) {
   using numeric_type = typename Eigen::MatrixBase<Derived>::value_type;
@@ -239,6 +250,21 @@ inline auto norm2(
   return m.template lpNorm<2>();
 }
 
+template <typename Derived>
+inline auto volume(const Eigen::MatrixBase<Derived>& m) {
+  return m.size();
+}
+
+template <typename Derived>
+inline auto abs_min(const Eigen::MatrixBase<Derived>& m) {
+  return m.array().abs().minCoeff();
+}
+
+template <typename Derived>
+inline auto abs_max(const Eigen::MatrixBase<Derived>& m) {
+  return m.array().abs().maxCoeff();
+}
+
 }  // namespace Eigen
 
 #ifndef TILEDARRAY_MATH_LINALG_DISPATCH_W_TTG
@@ -253,12 +279,12 @@ inline auto norm2(
     return scalapack::FN;                                           \
   return non_distributed::FN;
 #elif (TILEDARRAY_HAS_TTG && !TILEDARRAY_HAS_SCALAPACK)
-#define TILEDARRAY_MATH_LINALG_DISPATCH_W_TTG(FN, MATRIX)               \
-  TA_MAX_THREADS;                                                       \
-  if (get_linalg_backend() == LinearAlgebraBackend::TTG ||              \
-      TiledArray::math::linalg::detail::prefer_distributed(MATRIX))     \
-    return TiledArray::math::linalg::ttg::FN;                           \
-  if (get_linalg_backend() == LinearAlgebraBackend::ScaLAPACK)          \
+#define TILEDARRAY_MATH_LINALG_DISPATCH_W_TTG(FN, MATRIX)              \
+  TA_MAX_THREADS;                                                      \
+  if (get_linalg_backend() == LinearAlgebraBackend::TTG ||             \
+      TiledArray::math::linalg::detail::prefer_distributed(MATRIX))    \
+    return TiledArray::math::linalg::ttg::FN;                          \
+  if (get_linalg_backend() == LinearAlgebraBackend::ScaLAPACK)         \
     TA_EXCEPTION("ScaLAPACK linear algebra backend is not available"); \
   return non_distributed::FN;
 #elif !TILEDARRAY_HAS_TTG && TILEDARRAY_HAS_SCALAPACK
@@ -271,11 +297,11 @@ inline auto norm2(
     return scalapack::FN;                                           \
   return non_distributed::FN;
 #else  // !TILEDARRAY_HAS_TTG && !TILEDARRAY_HAS_SCALAPACK
-#define TILEDARRAY_MATH_LINALG_DISPATCH_W_TTG(FN, MATRIX)               \
-  TA_MAX_THREADS;                                                       \
-  if (get_linalg_backend() == LinearAlgebraBackend::TTG)                \
-    TA_EXCEPTION("TTG linear algebra backend is not available");        \
-  if (get_linalg_backend() == LinearAlgebraBackend::ScaLAPACK)          \
+#define TILEDARRAY_MATH_LINALG_DISPATCH_W_TTG(FN, MATRIX)              \
+  TA_MAX_THREADS;                                                      \
+  if (get_linalg_backend() == LinearAlgebraBackend::TTG)               \
+    TA_EXCEPTION("TTG linear algebra backend is not available");       \
+  if (get_linalg_backend() == LinearAlgebraBackend::ScaLAPACK)         \
     TA_EXCEPTION("ScaLAPACK linear algebra backend is not available"); \
   return non_distributed::FN;
 #endif  // !TILEDARRAY_HAS_TTG && !TILEDARRAY_HAS_SCALAPACK
@@ -297,12 +323,12 @@ inline auto norm2(
     return scalapack::FN;                                           \
   return non_distributed::FN;
 #elif TILEDARRAY_HAS_TTG && !TILEDARRAY_HAS_SCALAPACK
-#define TILEDARRAY_MATH_LINALG_DISPATCH_WO_TTG(FN, MATRIX)              \
-  TA_MAX_THREADS;                                                       \
-  if (get_linalg_backend() == LinearAlgebraBackend::TTG)                \
-    TA_EXCEPTION(TILEDARRAY_MATH_LINALG_DISPATCH_WO_TTG_STRINGIFY(      \
-        FN) " is not provided by the TTG backend");                     \
-  if (get_linalg_backend() == LinearAlgebraBackend::ScaLAPACK)          \
+#define TILEDARRAY_MATH_LINALG_DISPATCH_WO_TTG(FN, MATRIX)             \
+  TA_MAX_THREADS;                                                      \
+  if (get_linalg_backend() == LinearAlgebraBackend::TTG)               \
+    TA_EXCEPTION(TILEDARRAY_MATH_LINALG_DISPATCH_WO_TTG_STRINGIFY(     \
+        FN) " is not provided by the TTG backend");                    \
+  if (get_linalg_backend() == LinearAlgebraBackend::ScaLAPACK)         \
     TA_EXCEPTION("ScaLAPACK linear algebra backend is not available"); \
   return non_distributed::FN;
 #elif !TILEDARRAY_HAS_TTG && TILEDARRAY_HAS_SCALAPACK
@@ -315,11 +341,11 @@ inline auto norm2(
     return scalapack::FN;                                           \
   return non_distributed::FN;
 #else  // !TILEDARRAY_HAS_TTG && !TILEDARRAY_HAS_SCALAPACK
-#define TILEDARRAY_MATH_LINALG_DISPATCH_WO_TTG(FN, MATRIX)              \
-  TA_MAX_THREADS;                                                       \
-  if (get_linalg_backend() == LinearAlgebraBackend::TTG)                \
-    TA_EXCEPTION("TTG linear algebra backend is not available");        \
-  if (get_linalg_backend() == LinearAlgebraBackend::ScaLAPACK)          \
+#define TILEDARRAY_MATH_LINALG_DISPATCH_WO_TTG(FN, MATRIX)             \
+  TA_MAX_THREADS;                                                      \
+  if (get_linalg_backend() == LinearAlgebraBackend::TTG)               \
+    TA_EXCEPTION("TTG linear algebra backend is not available");       \
+  if (get_linalg_backend() == LinearAlgebraBackend::ScaLAPACK)         \
     TA_EXCEPTION("ScaLAPACK linear algebra backend is not available"); \
   return non_distributed::FN;
 #endif  // !TILEDARRAY_HAS_TTG && !TILEDARRAY_HAS_SCALAPACK
diff --git a/src/TiledArray/math/solvers/conjgrad.h b/src/TiledArray/math/solvers/conjgrad.h
index cacfd55d63..efabd59af7 100644
--- a/src/TiledArray/math/solvers/conjgrad.h
+++ b/src/TiledArray/math/solvers/conjgrad.h
@@ -29,6 +29,7 @@
 #include <TiledArray/math/linalg/basic.h>
 #include <TiledArray/math/solvers/diis.h>
 #include "TiledArray/dist_array.h"
+#include "TiledArray/type_traits.h"
 
 namespace TiledArray::math {
 
@@ -44,8 +45,8 @@ namespace TiledArray::math {
 /// stand-alone functions:
 ///   \li <tt> std::size_t volume(const D&) </tt> (returns the total number of elements)
 ///   \li <tt> D clone(const D&) </tt>, returns a deep copy
-///   \li <tt> value_type minabs_value(const D&) </tt>
-///   \li <tt> value_type maxabs_value(const D&) </tt>
+///   \li <tt> value_type abs_min(const D&) </tt>
+///   \li <tt> value_type abs_max(const D&) </tt>
 ///   \li <tt> void vec_multiply(D& a, const D& b) </tt> (element-wise multiply
 ///   of \c a by \c b )
 ///   \li <tt> value_type inner_product(const D& a, const D& b) </tt>
@@ -60,7 +61,7 @@ namespace TiledArray::math {
 // clang-format on
 template <typename D, typename F>
 struct ConjugateGradientSolver {
-  typedef typename D::numeric_type value_type;
+  typedef TiledArray::detail::numeric_t<D> value_type;
 
   /// \param a object of type F
   /// \param b RHS
@@ -73,8 +74,8 @@ struct ConjugateGradientSolver {
                         value_type convergence_target = -1.0) {
     std::size_t n = volume(preconditioner);
 
-    const bool use_diis = false;
-    DIIS<D> diis;
+    constexpr bool use_diis = false;
+    std::conditional_t<use_diis, DIIS<D>, char> diis{};
 
     // solution vector
     D XX_i;
@@ -120,7 +121,7 @@ struct ConjugateGradientSolver {
     scale(RR_i, -1.0);
     axpy(RR_i, 1.0, b);  // RR_i = b - a(XX_i)
 
-    if (use_diis) diis.extrapolate(XX_i, RR_i, true);
+    if constexpr (use_diis) diis.extrapolate(XX_i, RR_i, true);
 
     // z_0 = D^-1 . r_0
     ZZ_i = RR_i;
@@ -144,7 +145,7 @@ struct ConjugateGradientSolver {
       // r_i -= alpha_i Ap_i
       axpy(RR_i, -alpha_i, APP_i);
 
-      if (use_diis) diis.extrapolate(XX_i, RR_i, true);
+      if constexpr (use_diis) diis.extrapolate(XX_i, RR_i, true);
 
       const value_type r_ip1_norm = norm2(RR_i) / rhs_size;
       if (r_ip1_norm < convergence_target) {
diff --git a/src/TiledArray/math/solvers/diis.h b/src/TiledArray/math/solvers/diis.h
index 1407ff327e..86f58bfd5a 100644
--- a/src/TiledArray/math/solvers/diis.h
+++ b/src/TiledArray/math/solvers/diis.h
@@ -29,6 +29,7 @@
 #include <TiledArray/math/linalg/basic.h>
 #include "TiledArray/dist_array.h"
 #include "TiledArray/external/eigen.h"
+#include "TiledArray/type_traits.h"
 
 #include <Eigen/QR>
 #include <deque>
@@ -82,7 +83,7 @@ namespace TiledArray::math {
 template <typename D>
 class DIIS {
  public:
-  typedef typename D::numeric_type value_type;
+  typedef TiledArray::detail::numeric_t<D> value_type;
   typedef typename TiledArray::detail::scalar_t<value_type> scalar_type;
   typedef Eigen::Matrix<value_type, Eigen::Dynamic, Eigen::Dynamic,
                         Eigen::RowMajor>
diff --git a/src/TiledArray/tile_interface/clone.h b/src/TiledArray/tile_interface/clone.h
index 38c9dddf86..9c0221bf92 100644
--- a/src/TiledArray/tile_interface/clone.h
+++ b/src/TiledArray/tile_interface/clone.h
@@ -36,7 +36,7 @@ namespace TiledArray {
 /// \tparam Arg The tile argument type
 /// \param arg The tile argument to be permuted
 /// \return A (deep) copy of \c arg
-template <typename Arg>
+template <typename Arg, typename = decltype(std::declval<const Arg&>().clone())>
 inline auto clone(const Arg& arg) {
   return arg.clone();
 }
diff --git a/src/TiledArray/tile_op/tile_interface.h b/src/TiledArray/tile_op/tile_interface.h
index 6ab18a2384..5bf8219915 100644
--- a/src/TiledArray/tile_op/tile_interface.h
+++ b/src/TiledArray/tile_op/tile_interface.h
@@ -969,7 +969,8 @@ inline auto min(const Arg& arg) {
 /// \tparam Arg The tile argument type
 /// \param arg The argument to find the maximum
 /// \return A scalar that is equal to <tt>abs(max(arg))</tt>
-template <typename Arg>
+template <typename Arg,
+          typename = decltype(std::declval<const Arg&>().abs_max())>
 inline auto abs_max(const Arg& arg) {
   return arg.abs_max();
 }
@@ -979,7 +980,8 @@ inline auto abs_max(const Arg& arg) {
 /// \tparam Arg The tile argument type
 /// \param arg The argument to find the minimum
 /// \return A scalar that is equal to <tt>abs(min(arg))</tt>
-template <typename Arg>
+template <typename Arg,
+          typename = decltype(std::declval<const Arg&>().abs_min())>
 inline auto abs_min(const Arg& arg) {
   return arg.abs_min();
 }
@@ -991,7 +993,9 @@ inline auto abs_min(const Arg& arg) {
 /// \param left The left-hand argument tile
 /// \param right The right-hand argument tile
 /// \return A scalar that is equal to <tt>sum_i left[i] * right[i]</tt>
-template <typename Left, typename Right>
+template <typename Left, typename Right,
+          typename = decltype(std::declval<const Left&>().dot(
+              std::declval<const Right&>()))>
 inline auto dot(const Left& left, const Right& right) {
   return left.dot(right);
 }
@@ -1003,7 +1007,9 @@ inline auto dot(const Left& left, const Right& right) {
 /// \param left The left-hand argument tile
 /// \param right The right-hand argument tile
 /// \return A scalar that is equal to <tt>sum_i conj(left[i]) * right[i]</tt>
-template <typename Left, typename Right>
+template <typename Left, typename Right,
+          typename = decltype(std::declval<const Left&>().inner_product(
+              std::declval<const Right&>()))>
 inline auto inner_product(const Left& left, const Right& right) {
   return left.inner_product(right);
 }
diff --git a/tests/solvers.cpp b/tests/solvers.cpp
index 15335880a0..ea8c3ce5e5 100644
--- a/tests/solvers.cpp
+++ b/tests/solvers.cpp
@@ -167,6 +167,49 @@ struct validate<DistArray<Tile, Policy>> {
   }
 };
 
+// Eigen specializations
+
+template <>
+struct make_Ax<Eigen::VectorXd> {
+  using T = Eigen::VectorXd;
+
+  struct Ax {
+    Ax() : A_(3, 3) { A_ << 1, 2, 3, 2, 5, 8, 3, 8, 15; }
+    void operator()(const T& x, T& result) const { result = A_ * x; }
+    Eigen::MatrixXd A_;
+  };
+  Ax operator()() const { return Ax{}; }
+};
+
+template <>
+struct make_b<Eigen::VectorXd> {
+  using T = Eigen::VectorXd;
+
+  T operator()() const {
+    T result(3);
+    result << 1, 4, 0;
+    return result;
+  }
+};
+
+template <>
+struct make_pc<Eigen::VectorXd> {
+  using T = Eigen::VectorXd;
+
+  T operator()() const { return T::Ones(3); }
+};
+
+template <>
+struct validate<Eigen::VectorXd> {
+  using T = Eigen::VectorXd;
+
+  bool operator()(const T& x) const {
+    T ref(3);
+    ref << -6.5, 9., -3.5;
+    return (x - ref).norm() < 1e-11;
+  }
+};
+
 BOOST_AUTO_TEST_SUITE(solvers)
 
 BOOST_AUTO_TEST_CASE_TEMPLATE(conjugate_gradient, Array, array_types) {
@@ -178,4 +221,14 @@ BOOST_AUTO_TEST_CASE_TEMPLATE(conjugate_gradient, Array, array_types) {
   BOOST_CHECK(validate<Array>{}(x));
 }
 
+BOOST_AUTO_TEST_CASE(conjugate_gradient_eigen) {
+  using T = Eigen::VectorXd;
+  auto Ax = make_Ax<T>{}();
+  auto b = make_b<T>{}();
+  auto pc = make_pc<T>{}();
+  T x;
+  ConjugateGradientSolver<T, decltype(Ax)>{}(Ax, b, x, pc, 1e-11);
+  BOOST_CHECK(validate<T>{}(x));
+}
+
 BOOST_AUTO_TEST_SUITE_END()