diff --git a/src/tcviewer/settings.py b/src/tcviewer/settings.py
index 8f8e75b..35250d5 100644
--- a/src/tcviewer/settings.py
+++ b/src/tcviewer/settings.py
@@ -1,5 +1,10 @@
 from typing import Any, Tuple, List
-from PySide6 import *
+
+try:
+    from PySide6 import *
+    has_qt = True
+except ImportError:
+    has_qt = False
 
 settings = {
     'atom': {
@@ -14,71 +19,71 @@
     },
 }
 
-
-class SettingsTab(QtWidgets.QWidget):
-	def __init__(self):
-		super().__init__()
-		self.layout = QtWidgets.QGridLayout()
-		self.setLayout(self.layout)
-
-	def __enter__(self):
-		return self
-
-	def __exit__(self, *args):
-		...
-
-	def add(self, section: str = None, name: str = None, default: Any = None, range: Tuple[float] = None, options: List[str] = None):
-		row = self.layout.rowCount()
-		self.layout.addWidget(QtWidgets.QLabel('    ' + name + ':'), row, 0)
-
-	def add_checkbox(self, section: str = None, name: str = None, default: bool = True):
-		row = self.layout.rowCount()
-		self.layout.addWidget(QtWidgets.QLabel('    ' + name + ':'), row, 0)
-		widg = QtWidgets.QCheckBox()
-		widg.setCheckState(QtCore.Qt.CheckState.Checked if default else QtCore.Qt.CheckState.Unchecked)
-		self.layout.addWidget(widg, row, 1)
-
-	def add_spinbox(self, section: str = None, name: str = None, default: float = None, minimum: float = None, maximum: float = None, step: float = None, decimals: int = 2, suffix_text: str = None):
-		row = self.layout.rowCount()
-		self.layout.addWidget(QtWidgets.QLabel('    ' + name + ':'), row, 0)
-		widg = QtWidgets.QDoubleSpinBox()
-		if default:
-			widg.setValue(default)
-		if minimum:
-			widg.setMinimum(minimum)
-		if maximum:
-			widg.setMaximum(maximum)
-		if step:
-			widg.setSingleStep(step)
-		if decimals:
-			widg.setDecimals(decimals)
-
-		self.layout.addWidget(widg, row, 1)
-
-		if suffix_text:
-			self.layout.addWidget(QtWidgets.QLabel(suffix_text), row, 2)
-
-
-
-class SettingsWidget(QtWidgets.QTabWidget):
-	def __init__(self):
-		super().__init__()
-
-	def add_tab(self, tab_name: str):
-		widg = SettingsTab()
-		self.addTab(widg, tab_name)
-		return widg
-
-
-class DefaultSettings(SettingsWidget):
-	def __init__(self):
-		super().__init__()
-
-		with self.add_tab('Molecule') as tab:
-			tab.add_spinbox('Atom', 'Size Ratio', 1/2.4, minimum=0, step=0.05, decimals=3)
-			tab.add_checkbox('Atom', 'Draw Quadrants', True)
-			tab.add_spinbox('Atom', 'Quadrant Width', default=0.02, minimum=0, step=0.001, decimals=3, suffix_text='Å')
-		# self.add_tab('Bond')
+if has_qt:
+	class SettingsTab(QtWidgets.QWidget):
+		def __init__(self):
+			super().__init__()
+			self.layout = QtWidgets.QGridLayout()
+			self.setLayout(self.layout)
+
+		def __enter__(self):
+			return self
+
+		def __exit__(self, *args):
+			...
+
+		def add(self, section: str = None, name: str = None, default: Any = None, range: Tuple[float] = None, options: List[str] = None):
+			row = self.layout.rowCount()
+			self.layout.addWidget(QtWidgets.QLabel('    ' + name + ':'), row, 0)
+
+		def add_checkbox(self, section: str = None, name: str = None, default: bool = True):
+			row = self.layout.rowCount()
+			self.layout.addWidget(QtWidgets.QLabel('    ' + name + ':'), row, 0)
+			widg = QtWidgets.QCheckBox()
+			widg.setCheckState(QtCore.Qt.CheckState.Checked if default else QtCore.Qt.CheckState.Unchecked)
+			self.layout.addWidget(widg, row, 1)
+
+		def add_spinbox(self, section: str = None, name: str = None, default: float = None, minimum: float = None, maximum: float = None, step: float = None, decimals: int = 2, suffix_text: str = None):
+			row = self.layout.rowCount()
+			self.layout.addWidget(QtWidgets.QLabel('    ' + name + ':'), row, 0)
+			widg = QtWidgets.QDoubleSpinBox()
+			if default:
+				widg.setValue(default)
+			if minimum:
+				widg.setMinimum(minimum)
+			if maximum:
+				widg.setMaximum(maximum)
+			if step:
+				widg.setSingleStep(step)
+			if decimals:
+				widg.setDecimals(decimals)
+
+			self.layout.addWidget(widg, row, 1)
+
+			if suffix_text:
+				self.layout.addWidget(QtWidgets.QLabel(suffix_text), row, 2)
+
+
+
+	class SettingsWidget(QtWidgets.QTabWidget):
+		def __init__(self):
+			super().__init__()
+
+		def add_tab(self, tab_name: str):
+			widg = SettingsTab()
+			self.addTab(widg, tab_name)
+			return widg
+
+
+	class DefaultSettings(SettingsWidget):
+		def __init__(self):
+			super().__init__()
+
+			with self.add_tab('Molecule') as tab:
+				tab.add_spinbox('Atom', 'Size Ratio', 1/2.4, minimum=0, step=0.05, decimals=3)
+				tab.add_checkbox('Atom', 'Draw Quadrants', True)
+				tab.add_spinbox('Atom', 'Quadrant Width', default=0.02, minimum=0, step=0.001, decimals=3, suffix_text='Å')
+			# self.add_tab('Bond')
 
 
 if __name__ == '__main__':