To open the Structure Editor window:

• click the Structure Editor  button on the main tool bar.
  
  
• or choose the Tools | Structure Editor menu item.
  
  
• or open a structure by choosing the File | Open | Structure menu item and Structure Editor will start automatically.

Only one Structure Editor window can be opened at any one time in the program. If you click the Structure Editor button, or you choose the Tools | Structure Editor menu, and the Structure Editor is already opened, this window becomes active.

To begin drawing a chemical structure in Structure Editor, click one of the buttons on the vertical bar. Every time you click one of these buttons the shape of the cursor will change to visually represent the engaged drawing mode. The vertical buttons, in contrast to the horizontal buttons, are not represented in the menu. If the function of a button is not apparent from its appearance, simply point the cursor at this button using the mouse and a hint will be displayed. We recommend trying out all the various features on a test structure.