diff --git a/ChemistryLib/PhreeqcIOData/AqueousSolution.h b/ChemistryLib/PhreeqcIOData/AqueousSolution.h
index 715a58a3d62bf1c68e66aea2244b76afbe56758d..43532f62d19ce6a948c87effb457f0b72a6c916f 100644
--- a/ChemistryLib/PhreeqcIOData/AqueousSolution.h
+++ b/ChemistryLib/PhreeqcIOData/AqueousSolution.h
@@ -11,9 +11,12 @@
 #pragma once
 
 #include <iosfwd>
+#include <memory>
 #include <string>
 #include <vector>
 
+#include "MathLib/LinAlg/GlobalMatrixVectorTypes.h"
+#include "MathLib/LinAlg/MatrixVectorTraits.h"
 #include "Output.h"
 
 namespace ChemistryLib
@@ -24,10 +27,16 @@ namespace PhreeqcIOData
 {
 struct Component
 {
-    explicit Component(std::string name_) : name(std::move(name_)) {}
+    explicit Component(std::string name_,
+                       std::size_t const num_chemical_systems_)
+        : name(std::move(name_)),
+          amount(MathLib::MatrixVectorTraits<GlobalVector>::newInstance(
+              num_chemical_systems_))
+    {
+    }
 
     std::string const name;
-    double amount = std::numeric_limits<double>::quiet_NaN();
+    std::unique_ptr<GlobalVector> amount;
     static const ItemType item_type = ItemType::Component;
 };
 
@@ -37,9 +46,12 @@ struct AqueousSolution
                     double pressure_,
                     double pe_,
                     std::vector<Component>&& components_,
-                    ChargeBalance charge_balance_)
+                    ChargeBalance charge_balance_,
+                    std::size_t const num_chemical_systems_)
         : temperature(temperature_),
           pressure(pressure_),
+          pH(MathLib::MatrixVectorTraits<GlobalVector>::newInstance(
+              num_chemical_systems_)),
           pe(pe_),
           components(std::move(components_)),
           charge_balance(charge_balance_)
@@ -51,8 +63,8 @@ struct AqueousSolution
 
     double temperature;
     double pressure;
-    double pH = std::numeric_limits<double>::quiet_NaN();
     double pe;
+    std::unique_ptr<GlobalVector> pH;
     std::vector<Component> components;
     ChargeBalance const charge_balance;
 };
diff --git a/ChemistryLib/PhreeqcIOData/CreateSolutionComponent.cpp b/ChemistryLib/PhreeqcIOData/CreateSolutionComponent.cpp
index 44c0fce8422b462bcd12a88f9489c4d39f877ce5..3d9d25577b47325b589bfc6f812ffa7d22a70b1f 100644
--- a/ChemistryLib/PhreeqcIOData/CreateSolutionComponent.cpp
+++ b/ChemistryLib/PhreeqcIOData/CreateSolutionComponent.cpp
@@ -17,7 +17,7 @@ namespace ChemistryLib
 namespace PhreeqcIOData
 {
 std::vector<Component> createSolutionComponents(
-    BaseLib::ConfigTree const& config)
+    BaseLib::ConfigTree const& config, std::size_t const num_chemical_systems)
 {
     std::vector<Component> components;
     //! \ogs_file_param{prj__chemical_system__solution__components}
@@ -27,7 +27,7 @@ std::vector<Component> createSolutionComponents(
         //! \ogs_file_param{prj__chemical_system__solution__components__component}
         comp_config.getConfigParameterList<std::string>("component"))
     {
-        components.emplace_back(component_name);
+        components.emplace_back(component_name, num_chemical_systems);
     }
 
     return components;
diff --git a/ChemistryLib/PhreeqcIOData/CreateSolutionComponent.h b/ChemistryLib/PhreeqcIOData/CreateSolutionComponent.h
index 417450e9dac2319acd7b65572483082a49ecefb1..d745e90979c74df7e02274a90684b61ba6d01ddc 100644
--- a/ChemistryLib/PhreeqcIOData/CreateSolutionComponent.h
+++ b/ChemistryLib/PhreeqcIOData/CreateSolutionComponent.h
@@ -24,6 +24,6 @@ namespace PhreeqcIOData
 struct Component;
 
 std::vector<Component> createSolutionComponents(
-    BaseLib::ConfigTree const& config);
+    BaseLib::ConfigTree const& config, std::size_t const num_chemical_systems);
 }  // namespace PhreeqcIOData
 }  // namespace ChemistryLib