diff --git a/plasmoid/applet/bodr/kalzium_plasma.h b/plasmoid/applet/bodr/kalzium_plasma.h
--- a/plasmoid/applet/bodr/kalzium_plasma.h
+++ b/plasmoid/applet/bodr/kalzium_plasma.h
@@ -23,7 +23,7 @@
 
 #include "ui_config.h"
 
-class KDialog;
+class QDialog;
 class QFont;
 
 class KalziumPlasma : public Plasma::Applet
@@ -58,7 +58,7 @@
         QString m_currentSource;
 
         Ui::config ui;
-        KDialog *m_dialog;
+        QDialog *m_dialog;
 
         QFont m_font;
 };
diff --git a/plasmoid/applet/bodr/kalzium_plasma.cpp b/plasmoid/applet/bodr/kalzium_plasma.cpp
--- a/plasmoid/applet/bodr/kalzium_plasma.cpp
+++ b/plasmoid/applet/bodr/kalzium_plasma.cpp
@@ -14,15 +14,18 @@
 
 #include "kalzium_plasma.h"
 
-#include <KDialog>
 #include <KConfigGroup>
 #include <KFontDialog>
-#include <QLineEdit>
 
+#include <QDialog>
+#include <QLineEdit>
 #include <QDebug>
 #include <QPainter>
 #include <QPen>
 #include <QColor>
+#include <QDialogButtonBox>
+#include <QPushButton>
+#include <QVBoxLayout>
 
 KalziumPlasma::KalziumPlasma(QObject *parent, const QVariantList &args)
     : Plasma::Applet(parent, args),
@@ -133,16 +136,26 @@
 void KalziumPlasma::showConfigurationInterface()
 {
     if (m_dialog == 0) {
-        m_dialog = new KDialog;
+        m_dialog = new QDialog;
         m_dialog->setWindowIcon(QIcon::fromTheme("kalzium"));
-        m_dialog->setCaption(i18n("KalziumPlasma Configuration"));
+        m_dialog->setWindowTitle(i18n("KalziumPlasma Configuration"));
         ui.setupUi(m_dialog->mainWidget());
         m_dialog->mainWidget()->layout()->setMargin(0);
-        m_dialog->setButtons(KDialog::Ok | KDialog::Cancel | KDialog::Apply);
-        connect(m_dialog, SIGNAL(applyClicked()),
-                this, SLOT(configAccepted()));
-        connect(m_dialog, SIGNAL(okClicked()),
-                this, SLOT(configAccepted()));
+        QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok|QDialogButtonBox::Cancel|QDialogButtonBox::Apply);
+        QWidget *mainWidget = new QWidget(this);
+        QVBoxLayout *mainLayout = new QVBoxLayout;
+        m_dialog->setLayout(mainLayout);
+        mainLayout->addWidget(mainWidget);
+        QPushButton *okButton = buttonBox->button(QDialogButtonBox::Ok);
+        okButton->setDefault(true);
+        okButton->setShortcut(Qt::CTRL | Qt::Key_Return);
+        m_dialog->connect(buttonBox, &QDialogButtonBox::accepted, this, &KalziumPlasma::accept);
+        m_dialog->connect(buttonBox, &QDialogButtonBox::rejected, this, &KalziumPlasma::reject);
+        mainLayout->addWidget(buttonBox);
+        connect(okButton, &QPushButton::clicked,
+                this, &KalziumPlasma::configAccepted);
+        connect(buttonBox, &QDialogButtonBox::Apply::clicked,
+                this, &KalziumPlasma::configAccepted);
         connect(ui.fontSelectButton, SIGNAL(clicked()),
                 this, SLOT(showFontSelectDlg()));
     }
diff --git a/plasmoid/applet/concentrationPlasmoid/concentrationCalculator.cpp b/plasmoid/applet/concentrationPlasmoid/concentrationCalculator.cpp
--- a/plasmoid/applet/concentrationPlasmoid/concentrationCalculator.cpp
+++ b/plasmoid/applet/concentrationPlasmoid/concentrationCalculator.cpp
@@ -41,6 +41,7 @@
 #include <plasma/theme.h>
 
 #include <KConfigDialog>
+#include <KConfigGroup>
 
 using namespace KUnitConversion;
 
@@ -1282,8 +1283,10 @@
     ui.soluteMass->setChecked(m_soluteMass);
     ui.solventVolume->setChecked(m_solventVolume);
 
-    connect(parent, SIGNAL(applyClicked()), this, SLOT(configAccepted()));
-    connect(parent, SIGNAL(okClicked()), this, SLOT(configAccepted()));
+    connect(parent->okButton, &QPushButton::clicked,
+            this, &concentrationCalculator::configAccepted);
+    connect(parent->buttonBox, &QDialogButtonBox::Apply::clicked,
+                this, &concentrationCalculator::configAccepted);
 
     connect (ui.soluteMass, SIGNAL(toggled(bool)), parent, SLOT(settingsModified()));
     connect (ui.solventVolume, SIGNAL(toggled(bool)), parent, SLOT(settingsModified()));
diff --git a/plasmoid/applet/gasPlasmoid/gasCalculator.cpp b/plasmoid/applet/gasPlasmoid/gasCalculator.cpp
--- a/plasmoid/applet/gasPlasmoid/gasCalculator.cpp
+++ b/plasmoid/applet/gasPlasmoid/gasCalculator.cpp
@@ -40,6 +40,7 @@
 #include <plasma/theme.h>
 
 #include <KConfigDialog>
+#include <KConfigGroup>
 
 using namespace KUnitConversion;
 
@@ -656,8 +657,10 @@
 
     ui.ideal->setChecked(m_ideal);
 
-    connect(parent, SIGNAL(applyClicked()), this, SLOT(gasConfigAccepted()));
-    connect(parent, SIGNAL(okClicked()), this, SLOT(gasConfigAccepted()));
+    connect(parent->okButton, &QPushButton::clicked,
+            this, &gasCalculator::gasConfigAccepted);
+    connect(parent->buttonBox, &QDialogButtonBox::Apply::clicked,
+            this, &gasCalculator::gasConfigAccepted);
     connect (ui.ideal, SIGNAL(toggled(bool)), parent, SLOT(settingsModified()));
 }
 
diff --git a/plasmoid/applet/nuclearPlasmoid/kalziumdataobject.cpp b/plasmoid/applet/nuclearPlasmoid/kalziumdataobject.cpp
--- a/plasmoid/applet/nuclearPlasmoid/kalziumdataobject.cpp
+++ b/plasmoid/applet/nuclearPlasmoid/kalziumdataobject.cpp
@@ -29,7 +29,7 @@
 #include <QSvgRenderer>
 #include <QPainter>
 
-#include <klocale.h>
+#include <KLocalizedString>
 #include <QDebug>
 
 #include <kpixmapcache.h>
diff --git a/plasmoid/applet/nuclearPlasmoid/nuclearCalculator.cpp b/plasmoid/applet/nuclearPlasmoid/nuclearCalculator.cpp
--- a/plasmoid/applet/nuclearPlasmoid/nuclearCalculator.cpp
+++ b/plasmoid/applet/nuclearPlasmoid/nuclearCalculator.cpp
@@ -42,6 +42,7 @@
 #include <math.h>
 
 #include <KConfigDialog>
+#include <KConfigGroup>
 
 using namespace KUnitConversion;
 
@@ -646,8 +647,10 @@
 
     ui.massOnly->setChecked(m_massOnly);
 
-    connect(parent, SIGNAL(applyClicked()), this, SLOT(configAccepted()));
-    connect(parent, SIGNAL(okClicked()), this, SLOT(configAccepted()));
+    connect(parent->okButton, &QPushButton::clicked,
+            this, &nuclearCalculator::configAccepted);
+    connect(parent->buttonBox, &QDialogButtonBox::Apply::clicked,
+            this, &nuclearCalculator::configAccepted);
     connect(ui.massOnly, SIGNAL(toggled(bool)), parent, SLOT(settingsModified()));
 }
 
diff --git a/plasmoid/applet/psePlasmoid/Molmasscalculator.cpp b/plasmoid/applet/psePlasmoid/Molmasscalculator.cpp
--- a/plasmoid/applet/psePlasmoid/Molmasscalculator.cpp
+++ b/plasmoid/applet/psePlasmoid/Molmasscalculator.cpp
@@ -32,6 +32,10 @@
 
 // Plasma
 #include <plasma/theme.h>
+#include <KConfigGroup>
+#include <QDialogButtonBox>
+#include <QPushButton>
+#include <QVBoxLayout>
 
 // local
 
@@ -53,7 +57,7 @@
     m_triggerTimer->setSingleShot(true);
     m_triggerTimer->setInterval(700);
 
-    connect(m_triggerTimer, SIGNAL(timeout()), this, SLOT(ParseMolecule()));
+    connect(m_triggerTimer, &QTimer::timeout, this, &Molmasscalculator::ParseMolecule);
 
     // Needed for the Popupapplet
     setPopupIcon("kalzium");
@@ -160,10 +164,10 @@
     m_lineedit->setClearButtonEnabled(true);
     m_lineedit->setMinimumWidth(100);
     m_lineedit->setText(i18n("C2H5OH"));
-    connect(m_lineedit, SIGNAL(textEdited(QString)), m_triggerTimer, SLOT(start()));
+    connect(m_lineedit, &Plasma::LineEdit::textEdited, m_triggerTimer, &QTimer::start);
 
     m_switchButton = new Plasma::IconWidget();
-    connect(m_switchButton, SIGNAL(clicked()), this, SLOT(toggleTable()));
+    connect(m_switchButton, &Plasma::IconWidget::clicked, this, &graphicsWidget::toggleTable);
 
     TopLayout->addItem(MoleculeLabel);
     TopLayout->addItem(m_lineedit);
@@ -217,7 +221,17 @@
 
 void Molmasscalculator::createConfigurationInterface(KConfigDialog* parent)
 {
-    parent->setButtons(KDialog::Ok | KDialog::Cancel | KDialog::Apply);
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Ok|QDialogButtonBox::Cancel|QDialogButtonBox::Apply);
+    QWidget *mainWidget = new QWidget(this);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    parent->setLayout(mainLayout);
+    mainLayout->addWidget(mainWidget);
+    QPushButton *okButton = buttonBox->button(QDialogButtonBox::Ok);
+    okButton->setDefault(true);
+    okButton->setShortcut(Qt::CTRL | Qt::Key_Return);
+    parent->connect(buttonBox, &QDialogButtonBox::accepted, this, &createConfigurationInterface::accept);
+    parent->connect(buttonBox, &QDialogButtonBox::rejected, this, &createConfigurationInterface::reject);
+    mainLayout->addWidget(buttonBox);
 
     QWidget *widget = new QWidget(parent);
 
@@ -234,8 +248,10 @@
 
     m_ui.tabletyp->setCurrentIndex(m_PeriodWidget->getCurrentPseTyp());
 
-    connect(parent, SIGNAL(applyClicked()), this, SLOT(configAccepted()));
-    connect(parent, SIGNAL(okClicked()), this, SLOT(configAccepted()));
+    connect(parent->okButton, &QPushButton::clicked,
+            this, &Molmasscalculator::configAccepted);
+    connect(parent->buttonBox, &QDialogButtonBox::Apply::clicked,
+                this, &Molmasscalculator::configAccepted);
 
     connect(m_ui.showPeriodic, SIGNAL(toggled(bool)), parent, SLOT(settingsModified()));
     connect(m_ui.copyToCliboard, SIGNAL(toggled(bool)), parent, SLOT(settingsModified()));
diff --git a/src/calculator/calculator.h b/src/calculator/calculator.h
--- a/src/calculator/calculator.h
+++ b/src/calculator/calculator.h
@@ -20,7 +20,7 @@
 #ifndef CALCULATOR_H
 #define CALCULATOR_H
 
-#include <kdialog.h>
+#include <QDialog>
 #include "ui_calculator.h"
 
 #include "nuclearCalculator.h"
@@ -40,7 +40,7 @@
  *
  * @author Kashyap R Puranik
  */
-class calculator : public KDialog
+class calculator : public QDialog
 {
     Q_OBJECT
 
diff --git a/src/calculator/calculator.cpp b/src/calculator/calculator.cpp
--- a/src/calculator/calculator.cpp
+++ b/src/calculator/calculator.cpp
@@ -20,19 +20,33 @@
 #include "calculator.h"
 
 #include <QDebug>
-#include <kactioncollection.h>
-#include <kstandardaction.h>
-#include <ktoolinvocation.h>
 #include <QDialog>
+#include <QDialogButtonBox>
 #include <QIcon>
+#include <QPushButton>
+#include <QVBoxLayout>
+
+#include <KActionCollection>
+#include <KConfigGroup>
+#include <KHelpClient>
 #include <KLocalizedString>
-calculator::calculator(QWidget *parent) : KDialog(parent)
+#include <KStandardAction>
+#include <KToolInvocation>
+
+calculator::calculator(QWidget *parent) : QDialog(parent)
 {
     setWindowTitle(i18n("Chemical Calculator"));
-    setButtons(Help | Close);
-    setDefaultButton(Close);
-
-    ui.setupUi(mainWidget());
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Help|QDialogButtonBox::Close);
+    QWidget *mainWidget = new QWidget(this);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    setLayout(mainLayout);
+    mainLayout->addWidget(mainWidget);
+    connect(buttonBox, &QDialogButtonBox::accepted, this, &calculator::accept);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &calculator::reject);
+    mainLayout->addWidget(buttonBox);
+    buttonBox->button(QDialogButtonBox::Close)->setDefault(true);
+
+    ui.setupUi(mainWidget);
 
     int maxTextWidth = 0;
     QStyleOptionViewItem option;
@@ -77,7 +91,7 @@
     ui.tree->setCurrentItem(ui.tree->topLevelItem(0), 0, QItemSelectionModel::ToggleCurrent);
 
     // help clicked
-    connect(this, SIGNAL(helpClicked()), this, SLOT(slotHelp()));
+    connect(buttonBox->button(QDialogButtonBox::Help), &QPushButton::clicked, this, &calculator::slotHelp);
 }
 
 calculator :: ~calculator()
@@ -124,5 +138,5 @@
 
 void calculator::slotHelp()
 {
-  // KToolInvocation::invokeHelp("calculator", "kalzium","");
+    KHelpClient::invokeHelp("calculator", "kalzium");
 }
diff --git a/src/detailinfodlg.h b/src/detailinfodlg.h
--- a/src/detailinfodlg.h
+++ b/src/detailinfodlg.h
@@ -18,7 +18,6 @@
 
 #include <QUrl>
 #include <QMap>
-#include <KDialog>
 #include <KPageDialog>
 
 class DetailedGraphicalOverview;
diff --git a/src/detailinfodlg.cpp b/src/detailinfodlg.cpp
--- a/src/detailinfodlg.cpp
+++ b/src/detailinfodlg.cpp
@@ -112,11 +112,11 @@
     reloadContent();
 
   /* enableButton(User1, true);
-   enableButton(User2, true);
+   user2Button->setEnabled(true);
     if (m_elementNumber == 1) {
-        enableButton(User2, false);
+        user2Button->setEnabled(false);
     } else if (m_elementNumber == KalziumDataObject::instance()->numberOfElements()) {
-        enableButton(User1, false);
+        user1Button->setEnabled(false);
     }*/
 }
 
@@ -590,7 +590,7 @@
     if (url.isEmpty() || !url.isValid()) {
         return;
     }
-    KRun::runUrl(url, QStringLiteral("text/html"), nullptr);
+    KRun::runUrl(url, QStringLiteral("text/html"), this, KRun::RunFlags(), QString(), QByteArray());
 }
 
 void DetailedInfoDlg::slotHelp()
diff --git a/src/elementdataviewer.h b/src/elementdataviewer.h
--- a/src/elementdataviewer.h
+++ b/src/elementdataviewer.h
@@ -14,7 +14,7 @@
 #ifndef ELEMENTDATAVIEWER_H
 #define ELEMENTDATAVIEWER_H
 
-#include <kdialog.h>
+#include <QDialog>
 #include "ui_plotsetupwidget.h"
 #include "kalziumdataobject.h"
 #include "kalziumutils.h"
@@ -84,7 +84,7 @@
  * where you can setup the plot
  * @author Carsten Niehaus
  */
-class ElementDataViewer : public KDialog
+class ElementDataViewer : public QDialog
 {
     Q_OBJECT
 
diff --git a/src/elementdataviewer.cpp b/src/elementdataviewer.cpp
--- a/src/elementdataviewer.cpp
+++ b/src/elementdataviewer.cpp
@@ -18,20 +18,23 @@
 #include <kplotaxis.h>
 #include <kplotobject.h>
 
-#include <klocale.h>
-#include <kactioncollection.h>
-#include <kstandardaction.h>
-#include <ktoolinvocation.h>
-#include <kunitconversion/converter.h>
 #include "prefs.h"
+#include <KActionCollection>
 #include <KConfig>
-#include <KConfigWidgets/khelpclient.h>
+#include <KConfigGroup>
+#include <KHelpClient>
+#include <KStandardAction>
+#include <KToolInvocation>
+#include <KUnitConversion/Converter>
 
 //QT-Includes
+#include <QDebug>
+#include <QDialogButtonBox>
 #include <QKeyEvent>
 #include <QPen>
+#include <QPushButton>
 #include <QTimer>
-#include <QDebug>
+#include <QVBoxLayout>
 
 AxisData::AxisData(AXISTYPE type) : currentDataType(-1)
 {
@@ -49,17 +52,24 @@
 
 
 ElementDataViewer::ElementDataViewer(QWidget *parent)
-        : KDialog(parent),
+        : QDialog(parent),
         m_yData(new AxisData(AxisData::Y)),
         m_xData(new AxisData(AxisData::X))
 {
-    setCaption(i18n("Plot Data"));
-    setButtons(Help | Close);
-    setDefaultButton(Close);
+    setWindowTitle(i18n("Plot Data"));
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Help|QDialogButtonBox::Close);
+    QWidget *mainWidget = new QWidget(this);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    setLayout(mainLayout);
+    mainLayout->addWidget(mainWidget);
+    connect(buttonBox, &QDialogButtonBox::accepted, this, &ElementDataViewer::accept);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &ElementDataViewer::reject);
+    mainLayout->addWidget(buttonBox);
+    buttonBox->button(QDialogButtonBox::Close)->setDefault(true);
 
     KalziumDataObject *kdo  = KalziumDataObject::instance();
 
-    ui.setupUi(mainWidget());
+    ui.setupUi(mainWidget);
 
     m_timer = new QTimer(this);
     m_timer->setSingleShot(true);
@@ -75,24 +85,24 @@
     m_actionCollection = new KActionCollection (this);
     KStandardAction::quit(this, SLOT(close()), m_actionCollection);
 
-    connect(m_timer, SIGNAL(timeout()),
-            this, SLOT(drawPlot()));
-    connect(ui.KCB_y, SIGNAL(activated(int)),
-            this, SLOT(rangeChanged()));
-    connect(ui.KCB_x, SIGNAL(activated(int)),
-            this, SLOT(rangeChanged()));
-    connect(ui.comboElementLabels, SIGNAL(activated(int)),
-            this, SLOT(rangeChanged()));
-    connect(ui.comboElementType,SIGNAL(activated(int)),
-            this, SLOT(rangeChanged()));
-    connect(ui.from, SIGNAL(valueChanged(int)),
-            this, SLOT(rangeChanged()));
-    connect(ui.to, SIGNAL(valueChanged(int)),
-            this, SLOT(rangeChanged()));
-    connect(this, SIGNAL(helpClicked()),
-            this, SLOT(slotHelp()));
-    connect(ui.full, SIGNAL(clicked()),
-            this, SLOT(fullRange()));
+    connect(m_timer, &QTimer::timeout,
+            this, &ElementDataViewer::drawPlot);
+    connect(ui.KCB_y, QOverload<int>::of(&KComboBox::activated),
+            this, &ElementDataViewer::rangeChanged);
+    connect(ui.KCB_x, QOverload<int>::of(&KComboBox::activated),
+            this, &ElementDataViewer::rangeChanged);
+    connect(ui.comboElementLabels, QOverload<int>::of(&KComboBox::activated),
+            this, &ElementDataViewer::rangeChanged);
+    connect(ui.comboElementType, QOverload<int>::of(&KComboBox::activated),
+            this, &ElementDataViewer::rangeChanged);
+    connect(ui.from, QOverload<int>::of(&QSpinBox::valueChanged),
+            this, &ElementDataViewer::rangeChanged);
+    connect(ui.to, QOverload<int>::of(&QSpinBox::valueChanged),
+            this, &ElementDataViewer::rangeChanged);
+    connect(buttonBox->button(QDialogButtonBox::Help), &QPushButton::clicked,
+            this, &ElementDataViewer::slotHelp);
+    connect(ui.full, &QPushButton::clicked,
+            this, &ElementDataViewer::fullRange);
     drawPlot();
 
     resize(650, 500);
diff --git a/src/eqchemview.cpp b/src/eqchemview.cpp
--- a/src/eqchemview.cpp
+++ b/src/eqchemview.cpp
@@ -23,8 +23,6 @@
 #include <QClipboard>
 #include <QDebug>
 
-#include <klocale.h>
-
 #include <LineEditUrlDropEventFilter>
 
 #include "ui_equationview.h"
diff --git a/src/exportdialog.h b/src/exportdialog.h
--- a/src/exportdialog.h
+++ b/src/exportdialog.h
@@ -16,7 +16,7 @@
 
 #include <QListWidget>
 #include <element.h>
-#include <KDialog>
+#include <QDialog>
 #include "kalziumdataobject.h"
 #include "ui_exportdialog.h"
 
@@ -45,7 +45,7 @@
 /**
 * @author: Johannes Simon
 */
-class ExportDialog : public KDialog
+class ExportDialog : public QDialog
 {
     Q_OBJECT
 
@@ -64,6 +64,11 @@
 
 public slots:
     void slotOkClicked();
+    /**
+     * Open help page
+     */
+    void slotHelpRequested();
+
 };
 
 #endif // EXPORTDIALOG_H
diff --git a/src/exportdialog.cpp b/src/exportdialog.cpp
--- a/src/exportdialog.cpp
+++ b/src/exportdialog.cpp
@@ -15,11 +15,19 @@
 
 #include "kalziumutils.h"
 
-#include <QFont>
-#include <KMessageBox>
-#include <kdialog.h>
 #include <QDebug>
+#include <QDialog>
+#include <QDialogButtonBox>
+#include <QFont>
+#include <QPushButton>
+#include <QVBoxLayout>
+
+#include <KConfigGroup>
+#include <KGuiItem>
+#include <KHelpClient>
 #include <KLocalizedString>
+#include <KMessageBox>
+
 
 static const char HTML_HEADER[] =
     "<html>"
@@ -74,19 +82,28 @@
 }
 
 ExportDialog::ExportDialog(QWidget * parent)
-        : KDialog(parent),m_outputStream(nullptr)
+        : QDialog(parent),m_outputStream(nullptr)
 {
     qDebug() << "ExportDialog::ExportDialog";
-    setButtons(Help | User1 | Cancel);
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Cancel|QDialogButtonBox::Help);
+    QWidget *mainWidget = new QWidget(this);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    setLayout(mainLayout);
+    mainLayout->addWidget(mainWidget);
+    QPushButton *user1Button = new QPushButton;
+    buttonBox->addButton(user1Button, QDialogButtonBox::ActionRole);
+    connect(buttonBox, &QDialogButtonBox::accepted, this, &ExportDialog::accept);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &ExportDialog::reject);
+    mainLayout->addWidget(buttonBox);
     qDebug() << "ExportDialog: setButtons";
-    ui.setupUi(mainWidget());
-    qDebug() << "ExportDialog: ui.setupUi(mainWidget());";
-    setButtonGuiItem(User1, KGuiItem(i18n("OK")));
+    ui.setupUi(mainWidget);
+    qDebug() << "ExportDialog: ui.setupUi(mainWidget)";
+    KGuiItem::assign(user1Button, KGuiItem(i18n("OK")));
     qDebug() << "ExportDialog: setButtonGuiItem(User1, KGuiItem(i18n(\"OK\")));";
     ui.targetFile->setMode(KFile::File | KFile::Directory | KFile::LocalOnly);
     qDebug() << "ui.targetFile->setMode(KFile::File | KFile::Directory | KFile::LocalOnly);";
 
-    setCaption(i18n("Export Chemical Data"));
+    setWindowTitle(i18n("Export Chemical Data"));
     qDebug() << "ui.targetFile->setMode(KFile::File | KFile::Directory | KFile::LocalOnly);";
 
     populateElementList();
@@ -97,10 +114,10 @@
     ui.formatList->addItem(".csv (comma-separated data)", "csv");
     qDebug() << "ui.formatList->addItem(...);";
 
-    connect(this, SIGNAL(user1Clicked()), this, SLOT(slotOkClicked()));
-    qDebug() << "connect(this, SIGNAL(user1Clicked()), this, SLOT(slotOkClicked()));";
-    setHelp(QString(),"kalzium");
-    qDebug() << "setHelp(QString(),\"kalzium\");";
+    connect(user1Button, &QPushButton::clicked, this, &ExportDialog::slotOkClicked);
+    qDebug() << "connect(user1Button, SIGNAL(clicked()), this, SLOT(slotOkClicked()));";
+    connect(buttonBox, &QDialogButtonBox::helpRequested, this, &ExportDialog::slotHelpRequested);
+    qDebug() << "KHelpClient::invokeHelp(QString(), \"kalzium\");";
 }
 
 ExportDialog::~ExportDialog()
@@ -175,6 +192,11 @@
     done(0);
 }
 
+void ExportDialog::slotHelpRequested()
+{
+    KHelpClient::invokeHelp(QString(), "kalzium");
+}
+
 void ExportDialog::exportToHtml()
 {
     *m_outputStream << HTML_HEADER << "<table>\n";
diff --git a/src/isotopetable/isotopeitem.cpp b/src/isotopetable/isotopeitem.cpp
--- a/src/isotopetable/isotopeitem.cpp
+++ b/src/isotopetable/isotopeitem.cpp
@@ -28,7 +28,7 @@
 #include <QPainter>
 #include <QStyleOptionGraphicsItem>
 
-#include <klocale.h>
+#include <KLocalizedString>
 
 IsotopeItem::IsotopeItem(Isotope *i, qreal x, qreal y, qreal width, qreal height, QGraphicsItem *parent)
     : QAbstractGraphicsShapeItem(parent)
diff --git a/src/isotopetable/isotopetabledialog.h b/src/isotopetable/isotopetabledialog.h
--- a/src/isotopetable/isotopetabledialog.h
+++ b/src/isotopetable/isotopetabledialog.h
@@ -22,7 +22,7 @@
 
 #include "ui_isotopedialog.h"
 
-#include <kdialog.h>
+#include <QDialog>
 
 class IsotopeItem;
 
@@ -32,7 +32,7 @@
  * @author Pino Toscano
  * @author Carsten Niehaus
  */
-class IsotopeTableDialog : public KDialog
+class IsotopeTableDialog : public QDialog
 {
     Q_OBJECT
 
diff --git a/src/isotopetable/isotopetabledialog.cpp b/src/isotopetable/isotopetabledialog.cpp
--- a/src/isotopetable/isotopetabledialog.cpp
+++ b/src/isotopetable/isotopetabledialog.cpp
@@ -26,17 +26,25 @@
 
 #include <isotope.h>
 
-#include <klocale.h>
-
+#include <KConfigGroup>
 #include <QDebug>
-#include<prefs.h>
+#include <QDialogButtonBox>
+#include <QPushButton>
+#include <QVBoxLayout>
+#include <prefs.h>
 
-IsotopeTableDialog::IsotopeTableDialog(QWidget* parent) : KDialog(parent)
+IsotopeTableDialog::IsotopeTableDialog(QWidget* parent) : QDialog(parent)
 {
-    setCaption(i18n("Isotope Table"));
-    setButtons(Close);
-    setDefaultButton(Close);
-    ui.setupUi(mainWidget());
+    setWindowTitle(i18n("Isotope Table"));
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Close);
+    QWidget *mainWidget = new QWidget(this);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    setLayout(mainLayout);
+    mainLayout->addWidget(mainWidget);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &IsotopeTableDialog::reject);
+    mainLayout->addWidget(buttonBox);
+    buttonBox->button(QDialogButtonBox::Close)->setDefault(true);
+    ui.setupUi(mainWidget);
     ui.guide->setGuidedView(ui.gv);
 
     connect(ui.gv->scene(), SIGNAL(itemSelected(IsotopeItem*)),
diff --git a/src/kalzium.cpp b/src/kalzium.cpp
--- a/src/kalzium.cpp
+++ b/src/kalzium.cpp
@@ -70,6 +70,7 @@
 #include <QGridLayout>
 #include <KLocalizedString>
 #include <QStandardPaths>
+#include <QFileDialog>
 
 #define IDS_ELEMENTINFO     7
 
@@ -322,9 +323,7 @@
 
 void Kalzium::slotExportTable()
 {
-    QString fileName = KFileDialog::getSaveFileName(QUrl(), i18n("*.png *.xpm *.jpg *.svg"), //
-                       this,
-                       i18n("Save Kalzium's Table In"));
+    QString fileName = QFileDialog::getSaveFileName(this, i18n("Save Kalzium's Table In"), QString(), i18n("Image files (*.png *.xpm *.jpg *.svg)"));
 
     if (fileName.endsWith(QLatin1String(".svg"))) {
         m_periodicTable->generateSvg(fileName);
diff --git a/src/kalziumelementproperty.cpp b/src/kalziumelementproperty.cpp
--- a/src/kalziumelementproperty.cpp
+++ b/src/kalziumelementproperty.cpp
@@ -22,7 +22,7 @@
 #include "kalziumdataobject.h"
 #include "search.h"
 
-#include "klocale.h"
+#include <KLocalizedString>
 
 #include <prefs.h>
 
diff --git a/src/kalziumgradienttype.cpp b/src/kalziumgradienttype.cpp
--- a/src/kalziumgradienttype.cpp
+++ b/src/kalziumgradienttype.cpp
@@ -27,7 +27,7 @@
 #include <QVariant>
 #include <QDebug>
 
-#include <klocale.h>
+#include <KLocalizedString>
 
 #include <math.h>
 
diff --git a/src/kalziumnumerationtype.cpp b/src/kalziumnumerationtype.cpp
--- a/src/kalziumnumerationtype.cpp
+++ b/src/kalziumnumerationtype.cpp
@@ -21,7 +21,7 @@
 
 #include "kalziumdataobject.h"
 
-#include <klocale.h>
+#include <KLocalizedString>
 
 KalziumNumerationTypeFactory::KalziumNumerationTypeFactory()
 {
diff --git a/src/kalziumschemetype.cpp b/src/kalziumschemetype.cpp
--- a/src/kalziumschemetype.cpp
+++ b/src/kalziumschemetype.cpp
@@ -27,12 +27,10 @@
 #endif
 
 #include <QBrush>
-
-#include <klocale.h>
 #include <QDebug>
 #include <QStandardPaths>
 
-
+#include <KLocalizedString>
 
 KalziumSchemeTypeFactory::KalziumSchemeTypeFactory()
 {
diff --git a/src/kalziumutils.cpp b/src/kalziumutils.cpp
--- a/src/kalziumutils.cpp
+++ b/src/kalziumutils.cpp
@@ -20,7 +20,7 @@
 #include <QPainter>
 #include <QDebug>
 
-#include <klocale.h>
+#include <KLocalizedString>
 
 #include <element.h>
 #include <kunitconversion/converter.h>
diff --git a/src/kdeeduglossary.h b/src/kdeeduglossary.h
--- a/src/kdeeduglossary.h
+++ b/src/kdeeduglossary.h
@@ -11,7 +11,7 @@
 #ifndef KDEEDUGLOSSARY_H
 #define KDEEDUGLOSSARY_H
 
-#include <kdialog.h>
+#include <QDialog>
 #include <QUrl>
 
 class QDomDocument;
@@ -203,7 +203,7 @@
  * @author Pino Toscano
  * @author Carsten Niehaus
  */
-class GlossaryDialog : public KDialog
+class GlossaryDialog : public QDialog
 {
     Q_OBJECT
 
diff --git a/src/kdeeduglossary.cpp b/src/kdeeduglossary.cpp
--- a/src/kdeeduglossary.cpp
+++ b/src/kdeeduglossary.cpp
@@ -20,24 +20,28 @@
 
 #include "kdeeduglossary.h"
 
-#include <klocale.h>
-#include <khtml_part.h>
-#include <khtmlview.h>
-#include <ktreewidgetsearchline.h>
-#include <kactioncollection.h>
-
-#include <qevent.h>
-#include <qfile.h>
-#include <qheaderview.h>
-#include <qlabel.h>
-#include <qlayout.h>
-#include <qlist.h>
-#include <qregexp.h>
-#include <qsplitter.h>
-#include <qstringlist.h>
-#include <qtreewidget.h>
-#include <QDomDocument>
+#include <KActionCollection>
+#include <KConfigGroup>
+#include <KHTMLPart>
+#include <KHTMLView>
+#include <KLocalizedString>
+#include <KTreeWidgetSearchLine>
+
 #include <QDebug>
+#include <QDialogButtonBox>
+#include <QDomDocument>
+#include <QEvent>
+#include <QFile>
+#include <QHeaderView>
+#include <QLabel>
+#include <QLayout>
+#include <QList>
+#include <QPushButton>
+#include <QRegExp>
+#include <QSplitter>
+#include <QStringList>
+#include <QTreeWidget>
+#include <QVBoxLayout>
 
 static const int FirstLetterRole = 0x00b00a00;
 
@@ -313,19 +317,17 @@
     return m_backgroundpicture;
 }
 
-GlossaryDialog::GlossaryDialog(QWidget *parent) : KDialog(parent), d(new Private(this))
+GlossaryDialog::GlossaryDialog(QWidget *parent) : QDialog(parent), d(new Private(this))
 {
-    setCaption(i18n("Glossary"));
-    setButtons(Close);
-    setDefaultButton(Close);
+    setWindowTitle(i18n("Glossary"));
 
     //this string will be used for all items. If a backgroundpicture should
     //be used call Glossary::setBackgroundPicture().
     d->m_htmlbasestring = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\"><html><body%1>";
 
     QWidget *main = new QWidget(this);
-    setMainWidget(main);
     QVBoxLayout *vbox = new QVBoxLayout(main);
+    setLayout(vbox);
     vbox->setMargin(0);
 
     QHBoxLayout *hbox = new QHBoxLayout();
@@ -359,7 +361,12 @@
     connect(d->m_glosstree, SIGNAL(itemActivated(QTreeWidgetItem*,int)),
             this, SLOT(itemActivated(QTreeWidgetItem*,int)));
 
-    resize(600, 400);
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Close);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &GlossaryDialog::reject);
+    buttonBox->button(QDialogButtonBox::Close)->setDefault(true);
+    vbox->addWidget(buttonBox);
+
+    resize(800, 400);
 }
 
 GlossaryDialog::~GlossaryDialog()
@@ -372,7 +379,7 @@
     if (e->key() == Qt::Key_Return) {
         e->ignore();
     }
-    KDialog::keyPressEvent(e);
+    QDialog::keyPressEvent(e);
 }
 
 void GlossaryDialog::Private::displayItem(const QUrl &url, const KParts::OpenUrlArguments &, const KParts::BrowserArguments &)
diff --git a/src/legendwidget.h b/src/legendwidget.h
--- a/src/legendwidget.h
+++ b/src/legendwidget.h
@@ -20,8 +20,6 @@
 #ifndef LEGENDWIDGET_H
 #define LEGENDWIDGET_H
 
-#include <kdialog.h>
-
 #include "kalziumelementproperty.h"
 #include <QLabel>
 
diff --git a/src/legendwidget.cpp b/src/legendwidget.cpp
--- a/src/legendwidget.cpp
+++ b/src/legendwidget.cpp
@@ -21,12 +21,12 @@
 
 #include "prefs.h"
 
-#include <klocale.h>
-
 #include <QHBoxLayout>
 #include <QGridLayout>
 #include <QDebug>
 
+#include <KLocalizedString>
+
 LegendWidget::LegendWidget(QWidget *parent) : QWidget(parent)
 {
     m_update = true;
diff --git a/src/molcalcwidget.cpp b/src/molcalcwidget.cpp
--- a/src/molcalcwidget.cpp
+++ b/src/molcalcwidget.cpp
@@ -32,7 +32,7 @@
 
 #include <QDebug>
 #include <kiconloader.h>
-#include <klocale.h>
+#include <KLocalizedString>
 #include <QPushButton>
 #include <QLineEdit>
 
diff --git a/src/psetable/elementitem.cpp b/src/psetable/elementitem.cpp
--- a/src/psetable/elementitem.cpp
+++ b/src/psetable/elementitem.cpp
@@ -29,7 +29,7 @@
 #include "elementitem.h"
 
 #include <prefs.h>
-#include <klocale.h>
+#include <KLocalizedString>
 
 #include <QGraphicsSceneMouseEvent>
 #include <QPainter>
diff --git a/src/psetable/numerationitem.cpp b/src/psetable/numerationitem.cpp
--- a/src/psetable/numerationitem.cpp
+++ b/src/psetable/numerationitem.cpp
@@ -29,7 +29,7 @@
 #include "numerationitem.h"
 
 #include <prefs.h>
-#include <klocale.h>
+#include <KLocalizedString>
 
 #include <QPainter>
 #include <QStyleOption>
diff --git a/src/rsdialog.h b/src/rsdialog.h
--- a/src/rsdialog.h
+++ b/src/rsdialog.h
@@ -20,7 +20,7 @@
 #ifndef RSDIALOG_H
 #define RSDIALOG_H
 
-#include <kdialog.h>
+#include <QDialog>
 #include <QWidget>
 #include <QMap>
 
@@ -31,7 +31,7 @@
  *
  * @author Carsten Niehaus
  */
-class RSDialog : public KDialog
+class RSDialog : public QDialog
 {
     Q_OBJECT
 
diff --git a/src/rsdialog.cpp b/src/rsdialog.cpp
--- a/src/rsdialog.cpp
+++ b/src/rsdialog.cpp
@@ -20,29 +20,38 @@
 
 #include "rsdialog.h"
 
+#include <QDialogButtonBox>
+#include <QPushButton>
 #include <QRegExp>
+#include <QVBoxLayout>
 
 #include "kalziumdataobject.h"
 #include "kalziumutils.h"
 
+#include <KConfigGroup>
+#include <KHelpClient>
 #include <KLocalizedString>
-#include <KConfigWidgets/khelpclient.h>
 #include <KMessageBox>
 
-RSDialog::RSDialog(QWidget* parent) : KDialog(parent)
+RSDialog::RSDialog(QWidget* parent) : QDialog(parent)
 {
-    setCaption(i18n("Risks/Security Phrases"));
-    setButtons(Help | Close);
+    setWindowTitle(i18n("Risks/Security Phrases"));
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Help|QDialogButtonBox::Close);
+    QWidget *mainWidget = new QWidget(this);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    setLayout(mainLayout);
+    mainLayout->addWidget(mainWidget);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &RSDialog::reject);
+    mainLayout->addWidget(buttonBox);
 
     createRPhrases();
     createSPhrases();
 
-    ui.setupUi(mainWidget());
+    ui.setupUi(mainWidget);
 
     connect(ui.filterButton, SIGNAL(clicked()),
             this, SLOT(filter()));
-    connect(this, SIGNAL(helpClicked()),
-            this, SLOT(slotHelp()));
+    connect(buttonBox, &QDialogButtonBox::helpRequested, this, &RSDialog::slotHelp);
 
         filter();
 }
diff --git a/src/spectrumwidget.cpp b/src/spectrumwidget.cpp
--- a/src/spectrumwidget.cpp
+++ b/src/spectrumwidget.cpp
@@ -27,7 +27,6 @@
 
 #include <element.h>
 
-#include <klocale.h>
 #include <kunitconversion/converter.h>
 #include <math.h>
 
diff --git a/src/tableinfowidget.h b/src/tableinfowidget.h
--- a/src/tableinfowidget.h
+++ b/src/tableinfowidget.h
@@ -20,7 +20,7 @@
 #ifndef TABLEINFOWIDGET_H
 #define TABLEINFOWIDGET_H
 
-#include <kdialog.h>
+#include <QDialog>
 #include <QLabel>
 
 #include "kalziumschemetype.h"
diff --git a/src/tablesdialog.cpp b/src/tablesdialog.cpp
--- a/src/tablesdialog.cpp
+++ b/src/tablesdialog.cpp
@@ -14,14 +14,14 @@
 
 #include "tablesdialog.h"
 
-#include <klocale.h>
+#include <KLocalizedString>
 #include <QIcon>
 #include <kactioncollection.h>
 #include <kcombobox.h>
 #include <kpagewidgetmodel.h>
 #include <kstandardaction.h>
 #include <ktoolinvocation.h>
-#include <kdialog.h>
+#include <QDialog>
 
 #include <QApplication>
 #include <QClipboard>
@@ -31,6 +31,7 @@
 #include <QHeaderView>
 #include <Qt>
 #include <QTableWidget>
+#include <KConfigGroup>
 
 TablesDialog::TablesDialog(QWidget *parent) : KPageDialog(parent)
 {
diff --git a/src/tools/moleculeview.h b/src/tools/moleculeview.h
--- a/src/tools/moleculeview.h
+++ b/src/tools/moleculeview.h
@@ -15,7 +15,7 @@
 #ifndef MOLECULEVIEW_H
 #define MOLECULEVIEW_H
 
-#include <kdialog.h>
+#include <QDialog>
 #include <avogadro/qtgui/molecule.h>
 
 #include "ui_moleculeviewerwidget.h"
@@ -36,7 +36,7 @@
 /**
  * @author Carsten Niehaus
  */
-class MoleculeDialog : public KDialog
+class MoleculeDialog : public QDialog
 {
     Q_OBJECT
 
diff --git a/src/tools/moleculeview.cpp b/src/tools/moleculeview.cpp
--- a/src/tools/moleculeview.cpp
+++ b/src/tools/moleculeview.cpp
@@ -21,16 +21,16 @@
 #include <avogadro/qtgui/scenepluginmodel.h>
 #include <avogadro/qtgui/toolplugin.h>
 
+#include <QDebug>
 #include <QFileInfo>
 #include <QGLFormat>
-#include <QDebug>
-#include <KFileDialog>
+#include <QUrl>
+
+#include <KIO/Job>
 #include <KJob>
-#include <KMessageBox>
 #include <KLocalizedString>
-#include <QUrl>
-#include <knewstuff3/downloaddialog.h>
-#include <kio/job.h>
+#include <KMessageBox>
+#include <KNS3/DownloadDialog>
 
 #include "iowrapper.h"
 
@@ -42,12 +42,18 @@
 #endif
 #include <openbabel/forcefield.h>
 #include <QStandardPaths>
+#include <KConfigGroup>
+#include <QDialogButtonBox>
+#include <QPushButton>
+#include <KGuiItem>
+#include <QVBoxLayout>
+#include <QFileDialog>
 
 using namespace OpenBabel;
 using namespace Avogadro::QtGui;
 
 MoleculeDialog::MoleculeDialog(QWidget * parent)
-    : KDialog(parent)
+    : QDialog(parent)
     , m_path(QString())
     , m_periodicTable(nullptr)
 {
@@ -56,18 +62,29 @@
     defFormat.setSampleBuffers(true);
     QGLFormat::setDefaultFormat(defFormat);
 
-    setCaption(i18n("Molecular Editor"));
-    setButtons(User3 | User2 | User1 | Close);
+    setWindowTitle(i18n("Molecular Editor"));
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Close);
+    QWidget *mainWidget = new QWidget(this);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    setLayout(mainLayout);
+    mainLayout->addWidget(mainWidget);
+    QPushButton *user1Button = new QPushButton;
+    buttonBox->addButton(user1Button, QDialogButtonBox::ActionRole);
+    QPushButton *user2Button = new QPushButton;
+    buttonBox->addButton(user2Button, QDialogButtonBox::ActionRole);
+    QPushButton *user3Button = new QPushButton;
+    buttonBox->addButton(user3Button, QDialogButtonBox::ActionRole);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &MoleculeDialog::reject);
 
-    setDefaultButton(User1);
+    user1Button->setDefault(true);
 
-    setButtonGuiItem(User1, KGuiItem(i18n("Load Molecule"), "document-open", i18n("Loading a molecule")));
+    KGuiItem::assign(user1Button, KGuiItem(i18n("Load Molecule")));
 
-    setButtonGuiItem(User2, KGuiItem(i18n("Download New Molecules"), "get-hot-new-stuff", i18n("Download new molecule files")));
+    KGuiItem::assign(user2Button, KGuiItem(i18n("Download New Molecules")));
 
-    setButtonGuiItem(User3, KGuiItem(i18n("Save Molecule"), "document-save", i18n("Saving a molecule")));
+    KGuiItem::assign(user3Button, KGuiItem(i18n("Save Molecule")));
 
-    ui.setupUi(mainWidget());
+    ui.setupUi(mainWidget);
 
     // Attempt to set up the UFF forcefield
 //     m_forceField = OBForceField::FindForceField("UFF");
@@ -93,13 +110,16 @@
     connect(ui.glWidget->molecule(), &Avogadro::QtGui::Molecule::changed,
             this, &MoleculeDialog::slotUpdateStatistics);
 
-    connect(this, &KDialog::user1Clicked,
+    connect(user1Button, &QPushButton::clicked,
             this, &MoleculeDialog::slotLoadMolecule);
-    connect(this, &KDialog::user2Clicked,
+    connect(user2Button, &QPushButton::clicked,
             this, &MoleculeDialog::slotDownloadNewStuff);
-    connect(this, &KDialog::user3Clicked,
+    connect(user3Button, &QPushButton::clicked,
             this, &MoleculeDialog::slotSaveMolecule);
 
+    mainLayout->addWidget(buttonBox);
+
+
     // Check that we have managed to load up some tools and engines
     int nTools = ui.glWidget->tools().size();
     if (!nTools) {
@@ -133,15 +153,14 @@
     QString commonMoleculeFormats = i18n("Common molecule formats");
     QString allFiles = i18n("All files");
 
-    QString filename = KFileDialog::getOpenFileName(
-                       QUrl::fromLocalFile(m_path),
-                       "*.cml *.xyz *.ent *.pdb *.alc *.chm *.cdx *.cdxml *.c3d1 *.c3d2"
+    QString filename = QFileDialog::getOpenFileName(
+                       this,
+                       i18n("Choose a file to open"),
+                       m_path,
+                       commonMoleculeFormats + "(*.cml *.xyz *.ent *.pdb *.alc *.chm *.cdx *.cdxml *.c3d1 *.c3d2"
                        " *.gpr *.mdl *.mol *.sdf *.sd *.crk3d *.cht *.dmol *.bgf"
                        " *.gam *.inp *.gamin *.gamout *.tmol *.fract"
-                       " *.mpd *.mol2|" + commonMoleculeFormats + "\n"
-                       "* *.*|" + allFiles,
-                       this,
-                       i18n("Choose a file to open"));
+                       " *.mpd *.mol2);;" + allFiles + "(*.*)");
 
     loadMolecule(filename);
 }
@@ -193,14 +212,12 @@
 {
     QString commonMoleculeFormats = i18n("Common molecule formats");
     QString allFiles = i18n("All files");
-    QString filename = KFileDialog::getSaveFileName(QUrl(),
-                       "*.cml *.xyz *.ent *.pdb *.alc *.chm *.cdx *.cdxml *.c3d1 *.c3d2"
+    QString filename = QFileDialog::getSaveFileName(this, i18n("Choose a file to save to"), QString(),
+                       commonMoleculeFormats + " (*.cml *.xyz *.ent *.pdb *.alc *.chm *.cdx *.cdxml *.c3d1 *.c3d2"
                        " *.gpr *.mdl *.mol *.sdf *.sd *.crk3d *.cht *.dmol *.bgf"
                        " *.gam *.inp *.gamin *.gamout *.tmol *.fract"
-                       " *.mpd *.mol2|" + commonMoleculeFormats + "\n"
-                       "* *.*|" + allFiles,
-                       this,
-                       i18n("Choose a file to save to"));
+                       " *.mpd *.mol2);;" + allFiles + " (*.*)"
+                       );
 
     if (!filename.contains('.')) {
         filename.append(".cml");
diff --git a/src/tools/obconverter.h b/src/tools/obconverter.h
--- a/src/tools/obconverter.h
+++ b/src/tools/obconverter.h
@@ -25,14 +25,14 @@
 
 // OpenBabel includes
 #include <openbabel/obconversion.h>
-#include <KDialog>
+#include <QDialog>
 class QDialog;
 
 /**
  * @author Carsten Niehaus
  * @author Jerome Pansanel
  */
-class KOpenBabel : public KDialog
+class KOpenBabel : public QDialog
 {
     Q_OBJECT
 
@@ -93,6 +93,11 @@
      */
     void slotConvert();
 
+    /**
+     * Open help page
+     */
+    void slotHelpRequested();
+
 };
 
 #endif // OBCONVERTER_H
diff --git a/src/tools/obconverter.cpp b/src/tools/obconverter.cpp
--- a/src/tools/obconverter.cpp
+++ b/src/tools/obconverter.cpp
@@ -22,40 +22,51 @@
 #include "obconverter.h"
 
 // Qt includes
-#include <QRegExp>
-#include <QProcess>
-#include <QLinkedList>
+#include <QDebug>
+#include <QDialog>
 #include <QDialogButtonBox>
-#include <QVBoxLayout>
+#include <QFileDialog>
+#include <QLinkedList>
+#include <QProcess>
 #include <QPushButton>
-
+#include <QRegExp>
+#include <QUrl>
+#include <QVBoxLayout>
 
 // KDE includes
-#include <QDebug>
-#include <KMessageBox>
-#include <KFileDialog>
+#include <KConfigGroup>
+#include <KGuiItem>
+#include <KHelpClient>
 #include <KLocalizedString>
-#include <QUrl>
-#include <KDialog>
-#include <kdialogbuttonbox.h>
+#include <KMessageBox>
 using namespace std;
 using namespace OpenBabel;
 
 KOpenBabel::KOpenBabel(QWidget *parent)
-    : KDialog(parent)
+    : QDialog(parent)
 {
-    setCaption(i18n("OpenBabel Frontend"));
-    setButtons(Help | User1| Close);
-    setDefaultButton(User1);
+    setWindowTitle(i18n("OpenBabel Frontend"));
+    QDialogButtonBox *buttonBox = new QDialogButtonBox(QDialogButtonBox::Help|QDialogButtonBox::Close);
+    QWidget *mainWidget = new QWidget(this);
+    QVBoxLayout *mainLayout = new QVBoxLayout;
+    setLayout(mainLayout);
+    mainLayout->addWidget(mainWidget);
+    QPushButton *user1Button = new QPushButton;
+    buttonBox->addButton(user1Button, QDialogButtonBox::ActionRole);
+    connect(buttonBox, &QDialogButtonBox::rejected, this, &KOpenBabel::reject);
+    connect(user1Button, &QPushButton::clicked, this, &KOpenBabel::slotConvert);
+    connect(buttonBox, &QDialogButtonBox::helpRequested, this, &KOpenBabel::slotHelpRequested);
+
+    user1Button->setDefault(true);
 
     OBConvObject = new OBConversion();
 
-    ui.setupUi(mainWidget());
+    ui.setupUi(mainWidget);
 
-    setButtonGuiItem(User1, KGuiItem(i18n("Convert"), "edit-copy", i18n("Convert selected files")));
+    KGuiItem::assign(user1Button, KGuiItem(i18n("Convert")));
+    mainLayout->addWidget(buttonBox);
 
     setupWindow();
-    setHelp(QString(), "kalzium");
 }
 
 KOpenBabel::~KOpenBabel()
@@ -94,9 +105,6 @@
     connect(ui.selectAllFileButton,
             SIGNAL(clicked()), SLOT(slotSelectAll()));
 
-    connect(this,
-            SIGNAL(user1Clicked()), SLOT(slotConvert()));
-
     connect(ui.FileListView,
             SIGNAL(itemSelectionChanged()), SLOT(slotGuessInput()));
 }
@@ -115,16 +123,17 @@
 
     QStringList tmpList = InputType;
     tmpList.replaceInStrings(QRegExp("^"), "*.");
-    tmpList.replaceInStrings(QRegExp(" -- "), "|");
-    tmpList.replaceInStrings(QRegExp("/"), "\\/"); //escape all '/' (because of MimeTypes)
+    tmpList.replaceInStrings(QRegExp("(.*) -- (.*)"), "\\2(\\1)");
     //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
     // tmpList is now something like this:                                                                                      //
-    // "*.acr|ACR format [Read-only]", "*.alc|Alchemy format"                                                                   //
+    // "ACR format [Read-only] (*.acr)", "Alchemy format (*.alc)"                                                                   //
     //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 
-    QList<QUrl> fl = KFileDialog::getOpenUrls(
+    QList<QUrl> fl = QFileDialog::getOpenFileUrls(
+            this,
+            i18n("Open Molecule File"),
             QUrl(),
-            "*|" +i18n("All Files") + '\n' + tmpList.join("\n") //add all possible extensions like "*.cml *.mol"
+            i18n("All Files") + "(*.*);;" + tmpList.join(";;") //add all possible extensions like "*.cml *.mol"
             );
 
     foreach (const QUrl &u , fl) {
@@ -243,6 +252,11 @@
     }
 }
 
+void KOpenBabel::slotHelpRequested()
+{
+    KHelpClient::invokeHelp("kalzium-mainwindow", "kalzium");
+}
+
 void KOpenBabel::addFile(const QString &filename)
 {
     ui.FileListView->addItem(filename);