diff --git a/GUI/Model/Model/DatafilesTree.cpp b/GUI/Model/Model/DatafilesTree.cpp
index 4acb6acd5ed45bfa019cf8610c9ad7dccdfafd57..76a168f6c8b1204b4558e717196333df320d836c 100644
--- a/GUI/Model/Model/DatafilesTree.cpp
+++ b/GUI/Model/Model/DatafilesTree.cpp
@@ -92,7 +92,7 @@ QModelIndex DatafilesTree::indexOfHeadline(int rank) const
 QModelIndex DatafilesTree::index(int row, int column, const QModelIndex& parent) const
 {
     if (!hasIndex(row, column, parent))
-        return QModelIndex();
+        return {};
 
     if (!parent.isValid())
         return createIndex(row, column, nullptr);
@@ -101,16 +101,16 @@ QModelIndex DatafilesTree::index(int row, int column, const QModelIndex& parent)
         if (parent == indexOfHeadline(rank))
             return createIndex(row, column, m_items[rank - 1][row]);
 
-    return QModelIndex();
+    return {};
 }
 
 QModelIndex DatafilesTree::parent(const QModelIndex& index) const
 {
     if (!index.isValid())
-        return QModelIndex();
+        return {};
 
     if (index.internalPointer() == nullptr) // index is headline => no parent
-        return QModelIndex();
+        return {};
 
     return indexOfHeadline(itemForIndex(index)->rank());
 }
@@ -167,7 +167,7 @@ QVariant DatafilesTree::data(const QModelIndex& index, int role) const
             return qApp->palette().color(QPalette::Text);
 
         default:
-            return QVariant();
+            return {};
         }
     }
 
@@ -182,7 +182,7 @@ QVariant DatafilesTree::data(const QModelIndex& index, int role) const
     if (role == Qt::EditRole)
         return item->realItemName();
 
-    return QVariant();
+    return {};
 }
 
 Qt::ItemFlags DatafilesTree::flags(const QModelIndex& index) const
@@ -224,13 +224,13 @@ DatafileItem* DatafilesTree::itemForIndex(const QModelIndex& index) const
 QModelIndex DatafilesTree::indexForItem(DatafileItem* item) const
 {
     if (item == nullptr)
-        return QModelIndex();
+        return {};
 
     const int rank = item->rank();
     if (auto index = m_items[rank - 1].indexOf(item); index >= 0)
         return createIndex(index, 0, item);
 
-    return QModelIndex();
+    return {};
 }
 
 bool DatafilesTree::isHeadline(const QModelIndex& index) const
diff --git a/GUI/Model/Model/FitParameterModel.cpp b/GUI/Model/Model/FitParameterModel.cpp
index 0eba2f26ada4b126efbcff0f142d8eb14020f083..427e7a66bd822e3e6961c479cdb4a1eead94b8c1 100644
--- a/GUI/Model/Model/FitParameterModel.cpp
+++ b/GUI/Model/Model/FitParameterModel.cpp
@@ -76,7 +76,7 @@ QModelIndex FitParameterModel::index(int row, int column, const QModelIndex& par
 {
     if (!m_fitParameterContainer || row < 0 || column < 0 || column >= columnCount(QModelIndex())
         || (parent.isValid() && parent.column() != COL_NAME))
-        return QModelIndex();
+        return {};
 
     QObject* parent_item = itemForIndex(parent);
     ASSERT(parent_item);
@@ -114,16 +114,16 @@ QModelIndex FitParameterModel::index(int row, int column, const QModelIndex& par
             if (FitParameterLinkItem* linkItem = links.at(row))
                 return createIndex(row, column, linkItem->linkItem());
     }
-    return QModelIndex();
+    return {};
 }
 
 QModelIndex FitParameterModel::parent(const QModelIndex& child) const
 {
     if (!m_fitParameterContainer)
-        return QModelIndex();
+        return {};
 
     if (!child.isValid())
-        return QModelIndex();
+        return {};
 
     if (QObject* child_item = itemForIndex(child)) {
         if (QObject* parent_item = child_item->parent()) {
@@ -135,7 +135,7 @@ QModelIndex FitParameterModel::parent(const QModelIndex& child) const
             }
         }
     }
-    return QModelIndex();
+    return {};
 }
 
 int FitParameterModel::rowCount(const QModelIndex& parent) const
@@ -177,10 +177,10 @@ int FitParameterModel::columnCount(const QModelIndex& parent) const
 QVariant FitParameterModel::data(const QModelIndex& index, int role) const
 {
     if (!m_fitParameterContainer)
-        return QVariant();
+        return {};
 
     if (!index.isValid() || index.column() < 0 || index.column() >= NUM_COLUMNS)
-        return QVariant();
+        return {};
 
     if (QObject* item = itemForIndex(index)) {
         if (role == Qt::DisplayRole || role == Qt::EditRole) {
@@ -199,7 +199,7 @@ QVariant FitParameterModel::data(const QModelIndex& index, int role) const
         if (role == Qt::ToolTipRole && dynamic_cast<FitParameterLinkItem*>(item))
             return valueOfItem(item);
     }
-    return QVariant();
+    return {};
 }
 
 bool FitParameterModel::setData(const QModelIndex& index, const QVariant& value, int role)
@@ -300,7 +300,7 @@ QVariant FitParameterModel::headerData(int section, Qt::Orientation orientation,
         return m_columnNames.value(section);
     if (role == Qt::ToolTipRole)
         return m_columnToolTips.value(section);
-    return QVariant();
+    return {};
 }
 
 void FitParameterModel::onFitItemChanged()
@@ -330,7 +330,7 @@ void FitParameterModel::addColumn(FitParameterModel::EColumn id, const QString&
 QModelIndex FitParameterModel::indexOfItem(QObject* item) const
 {
     if (!m_fitParameterContainer)
-        return QModelIndex();
+        return {};
 
     ASSERT(item);
 
@@ -360,7 +360,7 @@ QModelIndex FitParameterModel::indexOfItem(QObject* item) const
             return createIndex(index, 0, item);
         }
     }
-    return QModelIndex();
+    return {};
 }
 
 QObject* FitParameterModel::itemForIndex(const QModelIndex& index) const
@@ -383,7 +383,7 @@ QVariant FitParameterModel::valueOfItem(QObject* item) const
     if (auto* link = dynamic_cast<LinkItem*>(item))
         return link->link();
 
-    return QVariant();
+    return {};
 }
 
 void FitParameterModel::setValueOfItem(QObject* item, const QVariant& value)
diff --git a/GUI/Model/Sample/MaterialModel.cpp b/GUI/Model/Sample/MaterialModel.cpp
index 20b04fb00d9c3aba708b13f8c36842043aa0c433..de973e9ca66fb71a08af7c7c3ff854f63f0c8cf1 100644
--- a/GUI/Model/Sample/MaterialModel.cpp
+++ b/GUI/Model/Sample/MaterialModel.cpp
@@ -30,15 +30,15 @@ const QString Material("Material");
 QColor suggestMaterialColor(const QString& name)
 {
     if (name.contains(materialMap.key(DefaultMaterials::Vacuum)))
-        return QColor(179, 242, 255);
+        return {179, 242, 255};
     if (name.contains(materialMap.key(DefaultMaterials::Substrate)))
-        return QColor(205, 102, 0);
+        return {205, 102, 0};
     if (name.contains(materialMap.key(DefaultMaterials::Default)))
         return QColor(Qt::green);
     if (name.contains(materialMap.key(DefaultMaterials::Core)))
-        return QColor(220, 140, 220);
+        return {220, 140, 220};
     if (name.contains(materialMap.key(DefaultMaterials::Particle)))
-        return QColor(146, 198, 255);
+        return {146, 198, 255};
 
     // return a random color
     static std::random_device r;
diff --git a/GUI/Support/Style/Style.cpp b/GUI/Support/Style/Style.cpp
index 85fb7e92dd31896262f834c7aa9ac7be64b86082..fc45a89cadfc11354831dcabaab5b9273d56566b 100644
--- a/GUI/Support/Style/Style.cpp
+++ b/GUI/Support/Style/Style.cpp
@@ -27,7 +27,7 @@ QSize FindSizeOfLetterM(const QWidget* widget)
     auto em = fontMetric.horizontalAdvance('M');
     auto fontAscent = fontMetric.ascent();
 
-    return QSize(em, fontAscent);
+    return {em, fontAscent};
 }
 
 QSize DefaultSizeOfLetterM()
diff --git a/GUI/View/Canvas/SpecularDataCanvas.cpp b/GUI/View/Canvas/SpecularDataCanvas.cpp
index eebd2eacc892269c0104ee9f1559f48a808008bc..f15d6b33c40c9f16c987d4378c0a8356138d089b 100644
--- a/GUI/View/Canvas/SpecularDataCanvas.cpp
+++ b/GUI/View/Canvas/SpecularDataCanvas.cpp
@@ -62,12 +62,12 @@ void SpecularDataCanvas::setJobOrDatafileItem(QObject* item)
 
 QSize SpecularDataCanvas::sizeHint() const
 {
-    return QSize(500, 400);
+    return {500, 400};
 }
 
 QSize SpecularDataCanvas::minimumSizeHint() const
 {
-    return QSize(128, 128);
+    return {128, 128};
 }
 
 QList<QAction*> SpecularDataCanvas::actionList()
diff --git a/GUI/View/Data/DatafileEditor.h b/GUI/View/Data/DatafileEditor.h
index fc1bb5a722bc57a0c95df769d56cf6bd438780fd..24247aba14214cc856ace9ee0d0a0b2e10025532 100644
--- a/GUI/View/Data/DatafileEditor.h
+++ b/GUI/View/Data/DatafileEditor.h
@@ -32,8 +32,8 @@ class DatafileEditor : public QWidget {
 public:
     DatafileEditor(QWidget* parent, ProjectDocument* document);
 
-    QSize sizeHint() const override { return QSize(64, 135); }
-    QSize minimumSizeHint() const override { return QSize(64, 128); }
+    QSize sizeHint() const override { return {64, 135}; }
+    QSize minimumSizeHint() const override { return {64, 128}; }
 
     //! Set current DatafileItem to display in instrument selector.
     void setDatafileItem(DatafileItem* realItem);
diff --git a/GUI/View/Info/CautionSign.cpp b/GUI/View/Info/CautionSign.cpp
index 323e26d6afda4985402040840d088a8679fddcbd..2614063b9b9d6a9185fd4c65733514a966d57851 100644
--- a/GUI/View/Info/CautionSign.cpp
+++ b/GUI/View/Info/CautionSign.cpp
@@ -113,5 +113,5 @@ QPoint CautionSign::positionForCautionSign() const
         }
     }
 
-    return QPoint(x, y);
+    return {x, y};
 }
diff --git a/GUI/View/Instrument/InstrumentLibraryEditor.cpp b/GUI/View/Instrument/InstrumentLibraryEditor.cpp
index 4ab3a1cbeb42e06d70be77f24a6a292cb8fe307f..fa94c2d808474648df9fea1606df0f774729f5c5 100644
--- a/GUI/View/Instrument/InstrumentLibraryEditor.cpp
+++ b/GUI/View/Instrument/InstrumentLibraryEditor.cpp
@@ -222,7 +222,7 @@ void InstrumentLibraryEditor::createWidgetsForCurrentInstrument()
         return;
     }
 
-    QWidget* w = new QWidget(m_scrollArea);
+    auto* w = new QWidget(m_scrollArea);
     auto* layout = new QVBoxLayout(w);
 
     auto title = QString("Summary (%1 instrument)").arg(currentInstrument->instrumentType());
diff --git a/GUI/View/Instrument/InstrumentListing.cpp b/GUI/View/Instrument/InstrumentListing.cpp
index cef624bea4649ea6e45371b2d36778404e2e0e27..7c7dd697a48cf7ab097be5c5c55711ac1d7d3ca1 100644
--- a/GUI/View/Instrument/InstrumentListing.cpp
+++ b/GUI/View/Instrument/InstrumentListing.cpp
@@ -110,12 +110,12 @@ InstrumentListing::~InstrumentListing()
 
 QSize InstrumentListing::sizeHint() const
 {
-    return QSize(170, 400);
+    return {170, 400};
 }
 
 QSize InstrumentListing::minimumSizeHint() const
 {
-    return QSize(96, 200);
+    return {96, 200};
 }
 
 QList<QAction*> InstrumentListing::toolbarActions() const
diff --git a/GUI/View/Instrument/InstrumentView.cpp b/GUI/View/Instrument/InstrumentView.cpp
index 0ce608985cb64474356f2f96cf6f4b7c2bb477f8..c51a70ce534b4da8fce4f944e09253ede30e6ed7 100644
--- a/GUI/View/Instrument/InstrumentView.cpp
+++ b/GUI/View/Instrument/InstrumentView.cpp
@@ -92,7 +92,7 @@ void InstrumentView::createWidgetsForCurrentInstrument()
         return;
     }
 
-    QWidget* w = new QWidget(m_scrollArea);
+    auto* w = new QWidget(m_scrollArea);
     auto* layout = new QVBoxLayout(w);
 
     //... Groupbox with instrument name and description (same layout for all instrument types)
diff --git a/GUI/View/Instrument/InstrumentsTreeModel.cpp b/GUI/View/Instrument/InstrumentsTreeModel.cpp
index d0bb5658b527987f311a658eb08d98748a18c1eb..bb7df5c9a1e3e20b55489232cec41aaad6df4d97 100644
--- a/GUI/View/Instrument/InstrumentsTreeModel.cpp
+++ b/GUI/View/Instrument/InstrumentsTreeModel.cpp
@@ -83,13 +83,13 @@ QModelIndex InstrumentsTreeModel::indexOfHeadline(InstrumentType type) const
         row++;
     }
 
-    return QModelIndex();
+    return {};
 }
 
 QModelIndex InstrumentsTreeModel::index(int row, int column, const QModelIndex& parent) const
 {
     if (!hasIndex(row, column, parent))
-        return QModelIndex();
+        return {};
 
     if (!parent.isValid())
         return createIndex(row, column, nullptr);
@@ -98,23 +98,23 @@ QModelIndex InstrumentsTreeModel::index(int row, int column, const QModelIndex&
         if (parent == indexOfHeadline(type))
             return createIndex(row, column, instrumentItemsOfType(type)[row]);
 
-    return QModelIndex();
+    return {};
 }
 
 QModelIndex InstrumentsTreeModel::parent(const QModelIndex& index) const
 {
     if (!index.isValid())
-        return QModelIndex();
+        return {};
 
     if (index.internalPointer() == nullptr) // index is headline => no parent
-        return QModelIndex();
+        return {};
 
     auto* item = itemForIndex(index);
     for (auto type : ::types)
         if (instrumentItemsOfType(type).contains(item))
             return indexOfHeadline(type);
 
-    return QModelIndex();
+    return {};
 }
 
 int InstrumentsTreeModel::columnCount(const QModelIndex& /*parent*/) const
@@ -257,13 +257,13 @@ InstrumentItem* InstrumentsTreeModel::itemForIndex(const QModelIndex& index) con
 QModelIndex InstrumentsTreeModel::indexForItem(InstrumentItem* item) const
 {
     if (item == nullptr)
-        return QModelIndex();
+        return {};
 
     for (auto type : ::types)
         if (auto row = instrumentItemsOfType(type).indexOf(item); row >= 0)
             return createIndex(row, 0, item);
 
-    return QModelIndex();
+    return {};
 }
 
 void InstrumentsTreeModel::removeItem(InstrumentItem* item)
diff --git a/GUI/View/JobControl/JobPropertiesTableModel.cpp b/GUI/View/JobControl/JobPropertiesTableModel.cpp
index 91fd845f07300781353ff1aeb967b241bf4327c3..1acad4122087fce2e1f403f27ff94d4218e38cf6 100644
--- a/GUI/View/JobControl/JobPropertiesTableModel.cpp
+++ b/GUI/View/JobControl/JobPropertiesTableModel.cpp
@@ -66,7 +66,7 @@ QVariant JobPropertiesTableModel::data(const QModelIndex& index, int role) const
     if ((role != Qt::DisplayRole && role != Qt::EditRole && role != Qt::ToolTipRole)
         || index.column() < 0 || index.column() >= NumColumns || index.row() < 0
         || index.row() >= NumRows || !m_item)
-        return QVariant();
+        return {};
 
     switch (index.column()) {
     case Column::Name:
@@ -93,14 +93,14 @@ QVariant JobPropertiesTableModel::data(const QModelIndex& index, int role) const
             std::optional<size_t> duration = m_item->duration();
             if (duration)
                 return QString("%1 s").arg(duration.value() / 1000., 0, 'f', 3);
-            return QVariant();
+            return {};
         }
         default:
-            return QVariant();
+            return {};
         }
     }
     default:
-        return QVariant();
+        return {};
     }
 }
 
@@ -110,7 +110,7 @@ QVariant JobPropertiesTableModel::headerData(int section, Qt::Orientation orient
     if (role == Qt::DisplayRole && orientation == Qt::Horizontal && section >= 0
         && section < NumColumns)
         return ColumnNames[section];
-    return QVariant();
+    return {};
 }
 
 Qt::ItemFlags JobPropertiesTableModel::flags(const QModelIndex& index) const
diff --git a/GUI/View/JobControl/JobSelector.cpp b/GUI/View/JobControl/JobSelector.cpp
index 0d602d416bdcba6987ccdf3a19615d6e2b9074d1..dc38b0d1595f8aca9cb4c53aac2b851168221d82 100644
--- a/GUI/View/JobControl/JobSelector.cpp
+++ b/GUI/View/JobControl/JobSelector.cpp
@@ -26,7 +26,7 @@ QVariant listToQVariant(const QList<int>& list)
     QList<QVariant> var_list;
     for (int val : list)
         var_list.push_back(QVariant(val));
-    return QVariant(var_list);
+    return {var_list};
 }
 
 QList<int> qVariantToList(const QVariant& var)
diff --git a/GUI/View/MaterialEditor/MaterialEditorModel.cpp b/GUI/View/MaterialEditor/MaterialEditorModel.cpp
index 1c2855b7cbeca93a9f5a02a66a77316b2d1ff80d..dfdecc1feb8bd89ca53b6a4ed5810721876f807d 100644
--- a/GUI/View/MaterialEditor/MaterialEditorModel.cpp
+++ b/GUI/View/MaterialEditor/MaterialEditorModel.cpp
@@ -180,7 +180,7 @@ QModelIndex MaterialEditorModel::indexFromMaterial(const QString& identifier) co
     for (int row = 0; row < materials.size(); row++)
         if (materials[row]->identifier() == identifier)
             return index(row, 0);
-    return QModelIndex();
+    return {};
 }
 
 QModelIndex MaterialEditorModel::indexFromMaterial(const MaterialItem* m) const
@@ -189,7 +189,7 @@ QModelIndex MaterialEditorModel::indexFromMaterial(const MaterialItem* m) const
     for (int row = 0; row < materials.size(); row++)
         if (materials[row] == m)
             return index(row, 0);
-    return QModelIndex();
+    return {};
 }
 
 QModelIndex MaterialEditorModel::first() const
diff --git a/GUI/View/Plotter/ColorMap.h b/GUI/View/Plotter/ColorMap.h
index 740f4e2a2b9ade75377e504510f0b6e96e29b80e..68a5d5a7111d447c418f9a93036cd2e30ac095d7 100644
--- a/GUI/View/Plotter/ColorMap.h
+++ b/GUI/View/Plotter/ColorMap.h
@@ -36,8 +36,8 @@ public:
 
     void itemToMap(Data2DItem* item);
 
-    QSize sizeHint() const override { return QSize(500, 400); }
-    QSize minimumSizeHint() const override { return QSize(128, 128); }
+    QSize sizeHint() const override { return {500, 400}; }
+    QSize minimumSizeHint() const override { return {128, 128}; }
 
     QCPColorScale* colorScale() { return m_colorScale; }
 
diff --git a/GUI/View/Plotter/SpecularPlot.h b/GUI/View/Plotter/SpecularPlot.h
index e42af315ec168de17ebeb1371b092fd0e3a8194d..28c38e4d7237a730ee025d00fcdfe1774aa28788 100644
--- a/GUI/View/Plotter/SpecularPlot.h
+++ b/GUI/View/Plotter/SpecularPlot.h
@@ -41,8 +41,8 @@ public:
     QList<Data1DItem*> data1DItems() const;
     Data1DItem* currentData1DItem() const;
 
-    QSize sizeHint() const override { return QSize(500, 400); }
-    QSize minimumSizeHint() const override { return QSize(128, 128); }
+    QSize sizeHint() const override { return {500, 400}; }
+    QSize minimumSizeHint() const override { return {128, 128}; }
 
     //! sets logarithmic scale
     void setLog();
diff --git a/GUI/View/Realspace/RealspacePanel.cpp b/GUI/View/Realspace/RealspacePanel.cpp
index 245e7dc6bc3f3c76ae3aab2cdc584666f26c1e42..7b9eee9081eef4edb0e0f167fe7e074c20684556 100644
--- a/GUI/View/Realspace/RealspacePanel.cpp
+++ b/GUI/View/Realspace/RealspacePanel.cpp
@@ -61,7 +61,7 @@ RealspacePanel::RealspacePanel(QWidget* parent)
 
 QSize RealspacePanel::sizeHint() const
 {
-    return QSize(300, 300);
+    return {300, 300};
 }
 
 RealspaceWidget* RealspacePanel::widget()
diff --git a/GUI/View/Sample/SampleListModel.cpp b/GUI/View/Sample/SampleListModel.cpp
index 8f3f3356e8626fe40552cee27e62a97cdc0a8383..7918aec2b4213662ac3499c951c6a36acdadcfa2 100644
--- a/GUI/View/Sample/SampleListModel.cpp
+++ b/GUI/View/Sample/SampleListModel.cpp
@@ -61,7 +61,7 @@ QVariant SampleListModel::data(const QModelIndex& index, int role) const
     if (role == Qt::EditRole)
         return item->sampleName();
 
-    return QVariant();
+    return {};
 }
 
 Qt::ItemFlags SampleListModel::flags(const QModelIndex& index) const
@@ -105,7 +105,7 @@ QModelIndex SampleListModel::indexForItem(SampleItem* item) const
     if (auto row = m_sampleItems->sampleItems().indexOf(item); row >= 0)
         return index(row, 0);
 
-    return QModelIndex();
+    return {};
 }
 
 void SampleListModel::removeSample(SampleItem* item)
diff --git a/GUI/View/Scene/MaskGraphicsView.h b/GUI/View/Scene/MaskGraphicsView.h
index 18f546f90f0ad6f1494cf95e86715cd3210871b0..a56a19e26b27a87cd2776a7fada0af143b97f4ff 100644
--- a/GUI/View/Scene/MaskGraphicsView.h
+++ b/GUI/View/Scene/MaskGraphicsView.h
@@ -27,8 +27,8 @@ class MaskGraphicsView : public QGraphicsView {
     Q_OBJECT
 public:
     MaskGraphicsView(MaskGraphicsScene* scene, QWidget* parent = nullptr);
-    QSize sizeHint() const override { return QSize(512, 512); }
-    QSize minimumSizeHint() const override { return QSize(128, 128); }
+    QSize sizeHint() const override { return {512, 512}; }
+    QSize minimumSizeHint() const override { return {128, 128}; }
 
 public slots:
     void onResetViewRequest();