boron doping

[tara]

When i replace a atom of silicon in the silicon lattice by boron ,it does not form any bonds with si atoms ,whereas when silicon atom is being replaced by alluminium atom it forms all bonds with other si atoms. Both boron and alluminium are in the same group of the periodic table but still in atk boron  doesnt form bond with silicon.

why is it so?can you help me with that 

[Umberto Martinez]

The bonds that you see in the Builder/Viewer do not have any physical meaning. Just a (nice) line when the distance between two atoms is shorter than a default cut-off radius.
So, nothing to worry about it.
check also http://quantumwise.com/forum/index.php?topic=2543.msg11885#msg11885

[Anders Blom]

Please post new questions in new threads, instead of reusing old ones.