|  | OGS
    | 
 <OpenGeoSysProject>
   <mesh>square_1x1_quad_1e0.vtu</mesh>
   <geometry>square_1x1.gml</geometry>
   <processes>
     <process>
       <name>SteadyStateDiffusion</name>
       <type>STEADY_STATE_DIFFUSION</type>
       <integration_order>2</integration_order>
       <process_variables>
         <process_variable>pressure</process_variable>
       </process_variables>
       <secondary_variables>
         <secondary_variable internal_name="darcy_velocity" output_name="v" />
       </secondary_variables>
     </process>
   </processes>
   <media>
     <medium id="0">
       <phases />
       <properties>
         <property>
           <name>diffusion</name>
           <type>Constant</type>
           <value>1</value>
         </property>
         <property>
           <name>reference_temperature</name>
           <type>Constant</type>
           <value>293.15</value>
         </property>
       </properties>
     </medium>
   </media>
   <time_loop>
     <processes>
       <process ref="SteadyStateDiffusion">
         <nonlinear_solver>basic_picard</nonlinear_solver>
         <convergence_criterion>
           <type>DeltaX</type>
           <norm_type>NORM2</norm_type>
           <abstol>1.e-6</abstol>
         </convergence_criterion>
         <time_discretization>
           <type>BackwardEuler</type>
         </time_discretization>
         <time_stepping>
           <type>SingleStep</type>
         </time_stepping>
       </process>
     </processes>
     <output>
       <type>VTK</type>
       <prefix>square_1e0_neumann</prefix>
       <variables>
         <variable>pressure</variable>
         <variable>v</variable>
       </variables>
       <suffix>ts{:timestep}_t_{:time}</suffix>
     </output>
   </time_loop>
   <parameters>
     <parameter>
       <name>p0</name>
       <type>Constant</type>
       <value>0</value>
     </parameter>
     <parameter>
       <name>p_neumann</name>
       <type>Constant</type>
       <value>1</value>
     </parameter>
     <parameter>
       <name>p_Dirichlet</name>
       <type>Constant</type>
       <value>1</value>
     </parameter>
   </parameters>
   <process_variables>
     <process_variable>
       <name>pressure</name>
       <components>1</components>
       <order>1</order>
       <initial_condition>p0</initial_condition>
       <boundary_conditions>
         <boundary_condition>
           <geometrical_set>square_1x1_geometry</geometrical_set>
           <geometry>left</geometry>
           <type>Dirichlet</type>
           <parameter>p_Dirichlet</parameter>
         </boundary_condition>
         <boundary_condition>
           <geometrical_set>square_1x1_geometry</geometrical_set>
           <geometry>bottom</geometry>
           <type>Dirichlet</type>
           <parameter>p_Dirichlet</parameter>
         </boundary_condition>
         <boundary_condition>
           <geometrical_set>square_1x1_geometry</geometrical_set>
           <geometry>right</geometry>
           <type>Neumann</type>
           <parameter>p_neumann</parameter>
         </boundary_condition>
       </boundary_conditions>
     </process_variable>
   </process_variables>
   <nonlinear_solvers>
     <nonlinear_solver>
       <name>basic_picard</name>
       <type>Picard</type>
       <max_iter>10</max_iter>
       <linear_solver>general_linear_solver</linear_solver>
     </nonlinear_solver>
   </nonlinear_solvers>
   <linear_solvers>
     <linear_solver>
       <name>general_linear_solver</name>
       <lis>-i cg -p jacobi -tol 1e-16 -maxiter 10000</lis>
       <eigen>
         <solver_type>CG</solver_type>
         <precon_type>DIAGONAL</precon_type>
         <max_iteration_step>10000</max_iteration_step>
         <error_tolerance>1e-16</error_tolerance>
       </eigen>
       <petsc>
         <prefix>gw</prefix>
         <parameters>-gw_ksp_type cg -gw_pc_type bjacobi -gw_ksp_rtol 1e-16 -gw_ksp_max_it 10000</parameters>
       </petsc>
     </linear_solver>
   </linear_solvers>
 </OpenGeoSysProject>