Chapter 2. Basic actions

To draw a simple molecule, you need to know several basic actions. In this chapter you'll find how to add, move and remove parts of your molecule.


To add a molecule, the program needs to be in add mode. This is the standard mode after starting the program.

Adding an atom

To add an atom, simply left click on a empty part of the document. An atom of the current element will be added. You can choose the element of desire on the left site of the window. molsKetch will remember your most recent choices.

Adding a bond

A bond can be added with a dragging move with the mouse. Depending on the start and endpoint of your movement, an extra atom will be added. You'll experience some gravity around the dynamic grid points or other atoms, to aid you in drawing consistent structures. A bond between two molecules will merge those molecules.

Changing the bond order

You can swap between the different bond orders by left clicking on a bond in add mode. You'll cycle between a single, double or triple bond.

Changing the bond type

molsKetch supports several different type of bonds, like stereo bonds. You can cycle between the bond types by left clicking on the bond, while holding "Shift".


If you want to remove a atom or a bond from a molecule, you have two options: a left click in the delete mode or a right click in the other modes. You can switch to Delete mode by selecting it from the Edit menu or by clicking on the corresponding button on the toolbar. Also, if an object is selected, you can remove it by pressing "Delete" on your keyboard.

Removing an atom

To remove a atom, left click on it in Delete mode or right click on it in the other modes. All bonds between this atom and the remainder of the molecule will be deleted.

Removing a bond

A bond can be removed by left clicking it in Delete mode and right clicking it in other modes. Multiple bonds can also be removed in this manor.

Removing a molecule

A molecule can be removed by a double click on a molecule in Delete mode. All atoms and bond of the molecule will be removed at once.


To move atoms or molecules, you'll need to be in Move mode. Use the edit menu or the toolbar to get there.

Moving an atom

To move a single or a few atoms select them first by clicking on or dragging around them. To move the highlighted atoms, click and drag them to their new position.

Moving a molecule

You can also move an entire molecule. To select a molecule, click on an empty place in the molecule. Next you can drag the molecule to its new position.