[CL] Get chemical formula of a component if given

ChemistryLib/PhreeqcIOData/AqueousSolution.h

@@ -32,9 +32,13 @@ namespace PhreeqcIOData
 {
 struct Component
 {
-    explicit Component(std::string name_) : name(std::move(name_)) {}
+    explicit Component(std::string name_, std::string chemical_formula_)
+        : name(std::move(name_)), chemical_formula(std::move(chemical_formula_))
+    {
+    }
 
     std::string const name;
+    std::string const chemical_formula;
     std::unique_ptr<GlobalVector> amount;
     static const ItemType item_type = ItemType::Component;
 };

ChemistryLib/PhreeqcIOData/CreateSolutionComponent.cpp

@@ -21,13 +21,18 @@ std::vector<Component> createSolutionComponents(
 {
     std::vector<Component> components;
     //! \ogs_file_param{prj__chemical_system__solution__components}
-    auto comp_config = config.getConfigSubtree("components");
+    auto components_config = config.getConfigSubtree("components");
+
     for (
-        auto const& component_name :
+        auto const& comp_config :
         //! \ogs_file_param{prj__chemical_system__solution__components__component}
-        comp_config.getConfigParameterList<std::string>("component"))
+        components_config.getConfigSubtreeList("component"))
     {
-        components.emplace_back(component_name);
+        auto const component_name = comp_config.getValue<std::string>();
+        auto const chemical_formula =
+            //! \ogs_file_attr{prj__chemical_system__solution__components__component__chemical_formula}
+            comp_config.getConfigAttribute<std::string>("chemical_formula", "");
+        components.emplace_back(component_name, chemical_formula);
     }
 
     return components;

Documentation/ProjectFile/prj/chemical_system/solution/components/component/a_chemical_formula.md

+chemical formula alternative to a component when defining water composition.

Documentation/ProjectFile/prj/chemical_system/solution/components/component/i_component.md

+define the element in the aqueous solution.

Documentation/ProjectFile/prj/chemical_system/solution/components/i_components.md

-define a list of elements in the initial solution.
+define a list of elements in the aqueous solution.