 <OpenGeoSysProject>

   <meshes>

     <mesh>Subsurface.vtu</mesh>

   </meshes>

   <geometry>cube_1x1x1.gml</geometry>

   <rasters>

     <raster>

       <file>raster_for_boundary.asc</file>

       <variable>heterogeneous_values</variable>

       <dimension>1</dimension>

     </raster>

   </rasters>

   <processes>

     <process>

       <name>LiquidFlow</name>

       <type>LIQUID_FLOW</type>

       <integration_order>2</integration_order>

       <process_variables>

         <process_variable>p</process_variable>

       </process_variables>

       <secondary_variables>

         <secondary_variable internal_name="darcy_velocity" output_name="v" />

       </secondary_variables>

       <specific_body_force>0.0 0.0 0</specific_body_force>

     </process>

   </processes>

   <media>

     <medium id="*">

       <phases>

         <phase>

           <type>AqueousLiquid</type>

           <properties>

             <property>

               <name>density</name>

               <type>Constant</type>

               <value>1.e3</value>

             </property>

             <property>

               <name>viscosity</name>

               <type>Constant</type>

               <value>1.e-3</value>

             </property>

           </properties>

         </phase>

       </phases>

       <properties>

         <property>

           <name>permeability</name>

           <type>Constant</type>

           <value>1.e-8 0 0 0 1.e-8 0 0 0 1.e-8</value>

         </property>

         <property>

           <name>reference_temperature</name>

           <type>Constant</type>

           <value>293.15</value>

         </property>

         <property>

           <name>porosity</name>

           <type>Constant</type>

           <value>0.1</value>

         </property>

         <property>

           <name>storage</name>

           <type>Constant</type>

           <value>0</value>

         </property>

       </properties>

     </medium>

   </media>

   <time_loop>

     <processes>

       <process ref="LiquidFlow">

         <nonlinear_solver>basic_picard</nonlinear_solver>

         <convergence_criterion>

           <type>DeltaX</type>

           <norm_type>NORM2</norm_type>

           <abstol>1.e-3</abstol>

         </convergence_criterion>

         <time_discretization>

           <type>BackwardEuler</type>

         </time_discretization>

         <time_stepping>

           <type>FixedTimeStepping</type>

           <t_initial>0.0</t_initial>

           <t_end>2</t_end>

           <timesteps>

             <pair>

               <repeat>1</repeat>

               <delta_t>1</delta_t>

             </pair>

           </timesteps>

         </time_stepping>

       </process>

     </processes>

     <include file="output_config.xml" />

   </time_loop>

   <parameters>

     <parameter>

       <name>P0</name>

       <type>Constant</type>

       <value>1</value>

     </parameter>

     <parameter>

       <name>p_Dirichlet_left</name>

       <type>Constant</type>

       <value>1</value>

     </parameter>

     <parameter>

       <name>p_Dirichlet_right</name>

       <type>Constant</type>

       <value>0</value>

     </parameter>

     <parameter>

       <name>raster_for_boundary_heterogeneous_values_1</name>

       <type>Raster</type>

     </parameter>

   </parameters>

   <process_variables>

     <process_variable>

       <name>p</name>

       <components>1</components>

       <order>1</order>

       <initial_condition>P0</initial_condition>

       <boundary_conditions>

         <boundary_condition>

           <geometrical_set>cube_1x1x1_geometry</geometrical_set>

           <geometry>left</geometry>

           <type>Dirichlet</type>

           <parameter>p_Dirichlet_left</parameter>

         </boundary_condition>

         <boundary_condition>

           <geometrical_set>cube_1x1x1_geometry</geometrical_set>

           <geometry>right</geometry>

           <type>Dirichlet</type>

           <parameter>p_Dirichlet_right</parameter>

         </boundary_condition>

         <boundary_condition>

           <geometrical_set>cube_1x1x1_geometry</geometrical_set>

           <geometry>top</geometry>

           <type>Neumann</type>

           <parameter>raster_for_boundary_heterogeneous_values_1</parameter>

         </boundary_condition>

       </boundary_conditions>

     </process_variable>

   </process_variables>

   <nonlinear_solvers>

     <nonlinear_solver>

       <name>basic_picard</name>

       <type>Picard</type>

       <max_iter>1000</max_iter>

       <linear_solver>general_linear_solver</linear_solver>

     </nonlinear_solver>

   </nonlinear_solvers>

   <linear_solvers>

     <linear_solver>

       <name>general_linear_solver</name>

       <lis>-i bicgstab -p jacobi -tol 1e-12 -maxiter 10000</lis>

       <petsc>

         <prefix>T</prefix>

         <parameters>-T_ksp_type bcgs -T_pc_type bjacobi -T_ksp_rtol 1e-16 -T_ksp_max_it 4000</parameters>

       </petsc>

       <eigen>

         <solver_type>BiCGSTAB</solver_type>

         <precon_type>DIAGONAL</precon_type>

         <max_iteration_step>10000</max_iteration_step>

         <error_tolerance>1e-12</error_tolerance>

       </eigen>

     </linear_solver>

   </linear_solvers>

 </OpenGeoSysProject>