[aydarsh]

Hi,

So far in class, we have learned about what the bond are of different molecules (NH₄, SF₆, etc), based upon the number of lone pairs, bonded atoms, etc.

Out of curiosity, how are such bond angles calculated mathematically, regardless of the type of atoms? I have seen a website that explained the bond angle for tetrahedral structures (http://mathcentral.uregina.ca/QQ/database/QQ.09.00/nishi1.html), but is there any method to calculate any bond angle, regardless of the number of atoms?

I was thinking that we would do something along the lines of coulomb's law and Lagrangian multipliers, but I don't actually know....

I don't really need specific calculations... I was just wondering about the general method itself...

Thanks!
Aydarsh

[Schrödinger]

Bond angles cannot be calculated if the only data available is the molecular formula. If you're referring to something like ML_n, where M is the central cation and L are the ligands around it, if n is unknown (even if it is known) we cannot generalize the bond angles. Ofcourse if the ligand field is symmetric (all L's being the same) we may think about simple polyhedra. But there are examples in literature where the bond angle is somewhere between those of 2 such possible polyhedra, when the ligands are not all the same - a hybrid mix, if you may.

[aydarsh]

Thanks!