Geometry distorts after optimization

[Jupinder93]

Hello

I have been trying to optimize fullerene molecule by adding a gas molecule to it till the point forces converge to 0.05eV/Angstrom. After optimization all the bonds break and i can see only constituent atoms spread in space. Why does the geometry of the fullerene and gas molecule distort after optimization? What can i do to correct it?

Thanks in advance!!

Regards
Jupinder

[Petr Khomyakov]

Seeing no sticks connecting atoms does not mean necessarily that there are no chemical bonds formed between the atoms. The Viewer has some geometrical bond length cutoff that can be controlled with Fuzz factor in the Graphics setting in the Viewer. You can also measure bond distances using the Measure Tools to see if those bond distances make sense.   

[Jupinder93]

Thanks for the reply!
I am using ATK 2013 version. Can you please guide me how i can alter the Fuzz factor in this version because i am unable to find this option in the viewer.

[Petr Khomyakov]

Unfortunately, 2013 version as well as any version older than 2018.06 is no longer supported. Please consider upgrading to a recent version of QuantumATK at https://www.synopsys.com/silicon/quantumatk.html.