How to determine bond strength

[TylerH]

Is it possible to determine the strength of a bond given the elements involved and the order of the bond? If so, how does one go about doing so?

The reason I'm asking is because I'm considering trying to code an analytical chemistry library as a way to increase my understanding of chemistry and applying my knowledge of programming.

 

[cgk]

Is it possible to determine the strength of a bond given the elements involved and the order of the bond?

Unfortunately, no. Figuring out the energetics of a molecule is a difficult process, and obtaining any kind of estimates reliable in a certain domain normally requires quantum mechanics of some sort (from simple semi-empirical Hamiltonians like AM1/PM3/DFTB/RM1 over density functional theory (DFT) to wave function methods). And even then it is very easy to get completely wrong results unless you know very well what you are doing. Some systems (e.g., most molecules containing 3d transition metal centers) are notoriously difficult to describe correctly, and getting reasonable results for them is an very active area of research.

That being said, there are also so called "classical force fields" (say, MM2, UFF) and group additivity schemes which have applications for molecular modeling or for estimating the energetics of compounds. But again, those things have tightly defined domains of applicability and even in those they may give bogus results.

 

[TylerH]

Wow, that is some intense math. Thanks for the very complete response. I don't think I'll be able to write a program to do the quantum chem part.