diff --git a/src/cell/cell_traits.hh b/src/cell/cell_traits.hh
index 7437fae..442e9b0 100644
--- a/src/cell/cell_traits.hh
+++ b/src/cell/cell_traits.hh
@@ -1,59 +1,58 @@
 /**
  * @file   cell_traits.hh
  *
  * @author Till Junge <till.junge@epfl.ch>
  *
  * @date   19 Jan 2018
  *
  * @brief  Provides traits for Eigen solvers to be able to use Cells
  *
  * Copyright © 2018 Till Junge
  *
  * µSpectre is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License as
  * published by the Free Software Foundation, either version 3, or (at
  * your option) any later version.
  *
  * µSpectre is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public License
  * along with µSpectre; see the file COPYING. If not, write to the
  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  * * Boston, MA 02111-1307, USA.
  *
  * Additional permission under GNU GPL version 3 section 7
  *
  * If you modify this Program, or any covered work, by linking or combining it
  * with proprietary FFT implementations or numerical libraries, containing parts
  * covered by the terms of those libraries' licenses, the licensors of this
  * Program grant you additional permission to convey the resulting work.
  */
 
 #include "common/common.hh"
 
 #include <Eigen/IterativeLinearSolvers>
 
 #ifndef SRC_CELL_CELL_TRAITS_HH_
 #define SRC_CELL_CELL_TRAITS_HH_
 
 namespace muSpectre {
 
-  template <class Cell>
-  class CellAdaptor;
+  template <class Cell> class CellAdaptor;
 
 }  // namespace muSpectre
 
 namespace Eigen {
   namespace internal {
     using Dim_t = muSpectre::Dim_t;  //!< universal index type
     using Real = muSpectre::Real;    //!< universal real value type
     template <class Cell>
     struct traits<muSpectre::CellAdaptor<Cell>>
         : public Eigen::internal::traits<Eigen::SparseMatrix<Real>> {};
   }  // namespace internal
 }  // namespace Eigen
 
 #endif  // SRC_CELL_CELL_TRAITS_HH_
diff --git a/src/materials/material_anisotropic.hh b/src/materials/material_anisotropic.hh
index 305d3da..5f9a7b6 100644
--- a/src/materials/material_anisotropic.hh
+++ b/src/materials/material_anisotropic.hh
@@ -1,154 +1,152 @@
 /**
  * @file   material_anisotropic.hh
  *
  * @author Ali Falsafi<ali.falsafi@epfl.ch>
  *
  * @date   9 Jul 2018
  *
  * @brief  Base class for materials (constitutive models)
  *
  * Copyright © 2017 Till Junge
  *
  * µSpectre is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation, either version 3, or (at
  * your option) any later version.
  *
  * µSpectre is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with GNU Emacs; see the file COPYING. If not, write to the
  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  * Boston, MA 02111-1307, USA.
  */
 #ifndef MATERIAL_ANISOTROPIC_H
 #define MATERIAL_ANISOTROPIC_H
 
 #include "materials/material_base.hh"
 #include "materials/material_muSpectre_base.hh"
 #include "common/common.hh"
 #include "common/T4_map_proxy.hh"
 
 namespace muSpectre {
-  template <Dim_t DimS, Dim_t DimM>
-  class MaterialAnisotropic;
+  template <Dim_t DimS, Dim_t DimM> class MaterialAnisotropic;
 
   // traits for anisotropic material
   template <Dim_t DimS, Dim_t DimM>
   struct MaterialMuSpectre_traits<MaterialAnisotropic<DimS, DimM>> {
     using Parent = MaterialMuSpectre_traits<void>;  //!< base for elasticity
 
     //! global field collection
     using GFieldCollection_t =
         typename MaterialBase<DimS, DimM>::GFieldCollection_t;
 
     //! expected map type for strain fields
     using StrainMap_t =
         MatrixFieldMap<GFieldCollection_t, Real, DimM, DimM, true>;
     //! expected map type for stress fields
     using StressMap_t = MatrixFieldMap<GFieldCollection_t, Real, DimM, DimM>;
     //! expected map type for tangent stiffness fields
     using TangentMap_t = T4MatrixFieldMap<GFieldCollection_t, Real, DimM>;
     //! declare what type of strain measure your law takes as input
     constexpr static auto strain_measure{StrainMeasure::GreenLagrange};
     //! declare what type of stress measure your law yields as output
     constexpr static auto stress_measure{StressMeasure::PK2};
 
     //! anisotropicity without internal variables
     using InternalVariables = std::tuple<>;
   };
 
   /**
    * Material implementation for anisotropic constitutive law
    */
   template <Dim_t DimS, Dim_t DimM = DimS>
   class MaterialAnisotropic
       : public MaterialMuSpectre<MaterialAnisotropic<DimS, DimM>, DimS, DimM> {
 
     //! base class
     using Parent = MaterialMuSpectre<MaterialAnisotropic, DimS, DimM>;
 
     using Stiffness_t = T4Mat<Real, DimM>;
 
     //! traits of this material
     using traits = MaterialMuSpectre_traits<MaterialAnisotropic>;
 
     //! this law does not have any internal variables
     using InternalVariables = typename traits::InternalVariables;
 
    public:
     EIGEN_MAKE_ALIGNED_OPERATOR_NEW
     using parent =
         MaterialMuSpectre<MaterialAnisotropic<DimS, DimM>, DimS, DimM>;
 
     //! global field collection
     using GFieldCollection_t =
         typename MaterialBase<DimS, DimM>::GFieldCollection_t;
 
     //! expected map type for tangent stiffness fields
     using Tangent_t = T4MatrixFieldMap<GFieldCollection_t, Real, DimM>;
 
     //! Default constructor
     MaterialAnisotropic() = delete;
 
     // constructor
     // a std::vector is utilized as the input of the constructor to
     // enable us to check its length so to prevent user mistake
     MaterialAnisotropic(std::string name, std::vector<Real> input_c);
 
     //! Copy constructor
     MaterialAnisotropic(const MaterialAnisotropic & other) = delete;
 
     //! Move constructor
     MaterialAnisotropic(MaterialAnisotropic && other) = delete;
 
     //! Destructor
     virtual ~MaterialAnisotropic() = default;
 
-    template <class s_t>
-    inline decltype(auto) evaluate_stress(s_t && E);
+    template <class s_t> inline decltype(auto) evaluate_stress(s_t && E);
 
     /**
      * evaluates both second Piola-Kirchhoff stress and stiffness given
      * the Green-Lagrange strain (or Cauchy stress and stiffness if
      * called with a small strain tensor) and the local stiffness tensor.
      */
     template <class s_t>
     inline decltype(auto) evaluate_stress_tangent(s_t && E);
 
     /**
      * return the empty internals tuple
      */
     InternalVariables & get_internals() { return this->internal_variables; };
 
     // takes the elements of the C and makes it:
     static auto c_maker(std::vector<Real> input) -> Stiffness_t;
 
    protected:
     Stiffness_t C;  //!< stiffness tensor
 
     //! empty tuple
     InternalVariables internal_variables{};
   };
 
   /* ---------------------------------------------------------------------- */
   template <Dim_t DimS, Dim_t DimM>
   template <class s_t>
   decltype(auto) MaterialAnisotropic<DimS, DimM>::evaluate_stress(s_t && E) {
     return Matrices::tensmult(this->C, E);
   }
 
   /* ---------------------------------------------------------------------- */
   template <Dim_t DimS, Dim_t DimM>
   template <class s_t>
   decltype(auto)
   MaterialAnisotropic<DimS, DimM>::evaluate_stress_tangent(s_t && E) {
     return std::make_tuple(evaluate_stress(E), this->C);
   }
 
 }  // namespace muSpectre
 
 #endif
diff --git a/src/materials/material_linear_elastic4.cc b/src/materials/material_linear_elastic4.cc
index 73be1db..6147043 100644
--- a/src/materials/material_linear_elastic4.cc
+++ b/src/materials/material_linear_elastic4.cc
@@ -1,79 +1,79 @@
 /**
  * @file   material_linear_elastic4.cc
  *
  * @author Richard Leute <richard.leute@imtek.uni-freiburg.de
  *
  * @date   15 March 2018
  *
  * @brief linear elastic material with distribution of stiffness properties.
  *        In difference to material_linear_elastic3 two Lame constants are
  *        stored per pixel instead of the whole elastic matrix C.
  *        Uses the MaterialMuSpectre facilities to keep it simple.
  *
  * Copyright © 2018 Till Junge
  *
  * µSpectre is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License as
  * published by the Free Software Foundation, either version 3, or (at
  * your option) any later version.
  *
  * µSpectre is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public License
  * along with µSpectre; see the file COPYING. If not, write to the
  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  * * Boston, MA 02111-1307, USA.
  *
  * Additional permission under GNU GPL version 3 section 7
  *
  * If you modify this Program, or any covered work, by linking or combining it
  * with proprietary FFT implementations or numerical libraries, containing parts
  * covered by the terms of those libraries' licenses, the licensors of this
  * Program grant you additional permission to convey the resulting work.
  */
 
-#include "materials/material_linear_elastic4.hh"
+#include "material_linear_elastic4.hh"
 
 namespace muSpectre {
 
   /* ---------------------------------------------------------------------- */
   template <Dim_t DimS, Dim_t DimM>
   MaterialLinearElastic4<DimS, DimM>::MaterialLinearElastic4(std::string name)
       : Parent{name}, lambda_field{make_field<Field_t>(
                           "local first Lame constant", this->internal_fields)},
         mu_field{
             make_field<Field_t>("local second Lame constant(shear modulus)",
                                 this->internal_fields)},
         internal_variables{lambda_field.get_const_map(),
                            mu_field.get_const_map()} {}
 
   /* ---------------------------------------------------------------------- */
   template <Dim_t DimS, Dim_t DimM>
   void MaterialLinearElastic4<DimS, DimM>::add_pixel(
       const Ccoord_t<DimS> & /*pixel*/) {
     throw std::runtime_error(
         "this material needs pixels with Youngs modulus and Poisson ratio.");
   }
 
   /* ---------------------------------------------------------------------- */
   template <Dim_t DimS, Dim_t DimM>
   void
   MaterialLinearElastic4<DimS, DimM>::add_pixel(const Ccoord_t<DimS> & pixel,
                                                 const Real & Young_modulus,
                                                 const Real & Poisson_ratio) {
     this->internal_fields.add_pixel(pixel);
     // store the first(lambda) and second(mu) Lame constant in the field
     Real lambda = Hooke::compute_lambda(Young_modulus, Poisson_ratio);
     Real mu = Hooke::compute_mu(Young_modulus, Poisson_ratio);
     this->lambda_field.push_back(lambda);
     this->mu_field.push_back(mu);
   }
 
   template class MaterialLinearElastic4<twoD, twoD>;
   template class MaterialLinearElastic4<twoD, threeD>;
   template class MaterialLinearElastic4<threeD, threeD>;
 
 }  // namespace muSpectre