# Extending molecules with a different atom type is cumbersome

**URL:** <https://discuss.avogadro.cc/t/extending-molecules-with-a-different-atom-type-is-cumbersome/859>\
**Category:** Development\
**Created:** [February 20, 2008, 6:35pm UTC](https://discuss.avogadro.cc/t/extending-molecules-with-a-different-atom-type-is-cumbersome/859 "2008-02-20T18:35:33Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![SourceForge\_net](https://discuss.avogadro.cc/letter_avatar_proxy/v4/letter/s/71c47a/32.png) [@SourceForge\_net](https://discuss.avogadro.cc/u/SourceForge_net)\
**Post date:** [February 20, 2008, 6:35pm UTC](https://discuss.avogadro.cc/t/extending-molecules-with-a-different-atom-type-is-cumbersome/859/1 "2008-02-20T18:35:33Z")

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Bugs item #1898086, was opened at 2008-02-20 19:35  
Message generated for change (Tracker Item Submitted) made by Item Submitter  
You can respond by visiting:  
[https://sourceforge.net/tracker/?func=detail&atid=835077&aid=1898086&group\_id=165310](https://sourceforge.net/tracker/?func=detail&atid=835077&aid=1898086&group_id=165310)

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Category: None  
Group: None  
Status: Open  
Resolution: None  
Priority: 5  
Private: No  
Submitted By: Michael Banck (mbanck)  
Assigned to: Nobody/Anonymous (nobody)  
Summary: Extending molecules with a different atom type is cumbersome

Initial Comment:  
In draw mode, if I have a particular atom type selected, and I click-drag on an atom with a different atom type, that atom is immediately converted to the selected atom type. I am not sure whether this is in intentional, but it looks like a usability problem to me.

I would rather expect avogadro to wait till I finish the drag operation (release the mouse pointer) and see whether I am still on that atom, and only convert then. Right now, it seems I have to extend a molecule backwards, i.e. first choose the new atom position and then drag the bond back to the atom of the molecule I want to extend from.

Little ASCII demonstration:

I want to draw H-O-H.

I have so far:

H-O

I select Hydrogen as atom type.

I click on the Oxygen and keep the mouse button pressed.

I get:

H-H

I expect:

H-O

and after dragging:

H-O-H

* * *

You can respond by visiting:  
[https://sourceforge.net/tracker/?func=detail&atid=835077&aid=1898086&group\_id=165310](https://sourceforge.net/tracker/?func=detail&atid=835077&aid=1898086&group_id=165310)