I attached the keybind I proposed to be added to the
/etc/xdg/openbox/LXDE/rc.xml file.
--- /etc/xdg/openbox/LXDE/rc.xml 2017-01-21 00:09:24.000000000 +0100
+++ new.xml 2020-06-04 22:22:44.763240643 +0200
@@ -310,6 +310,44 @@
<keybind key="XF86Display">
<action name="Execute"><command>lxrandr</command></action>
</keybind>
+
+ <!-- Put a window into a half screen -->
+ <keybind key="W-Left">
+ <action name="Unmaximize" />
+ <action name="MoveResizeTo">
+ <x>0</x>
+ <y>0</y>
+ <width>50%</width>
+ <height>100%</height>
+ </action>
+ </keybind>
+ <keybind key="W-Right">
+ <action name="Unmaximize" />
+ <action name="MoveResizeTo">
+ <x>-0</x>
+ <y>0</y>
+ <width>50%</width>
+ <height>100%</height>
+ </action>
+ </keybind>
+ <keybind key="W-Up">
+ <action name="Unmaximize" />
+ <action name="MoveResizeTo">
+ <x>0</x>
+ <y>0</y>
+ <width>100%</width>
+ <height>50%</height>
+ </action>
+ </keybind>
+ <keybind key="W-Down">
+ <action name="Unmaximize" />
+ <action name="MoveResizeTo">
+ <x>0</x>
+ <y>-0</y>
+ <width>100%</width>
+ <height>50%</height>
+ </action>
+ </keybind>
</keyboard>
