Groups-Repetition units

How to create a Repetition unit or an SRU

with the Repeating Group tool


After the dialog closes, the repetition unit is established.

with Selection


After the dialog closes, the repetition unit is established.

Please, remember:


  • one atom has been selected and

  • the repetition pattern is the default value (ht) and

  • the repetition count is a range starting with 1-...

the structure will be exported as a Link node.

How to modify a Repeating Unit

You can change the range and the pattern of the repetition by opening the Repeating group dialog.


With the active Repeating group tool hover over the group on the canvas with the mouse cursor. When the elements of the group are highlighted in grey, left-click within the brackets.
In the opening Repeating group dialog you can change the current values.

Delete a Repeating Unit

Right-click on the structure within the brackets, then select Ungroup from the menu.

When you modify the atoms or bonds in the group, it will automatically ungroup.