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**Nihilo**View PostChemists cannot use the full SchrÃ¶dinger Equations to solve their atom behaviours, becaues they involve the interactions of more than a few particles. To derive anything useful quantum chemistry is a semi-empirical field. This means that they use the depricated, very early and semi-classical quantum mechanics of de Broglie and bolt on discrete parts of other theories (in this case, Special Relativity) as they see fit and as far as it gives results consistent with observations.

Quantum Electrodynamics (QED) is the distant successor to early quantum mechanics (along with the other quantum field theories) and it isn't quantum mechanics with a relativity bolt-on correction, but is relativistic

*in its nature*. It fully incorporates the earlier theories from a century ago, and is bigger and better than both. QED is the most tested and most precisely accurate theortical model that humanity has ever produced *it really doesn't stand in second place to any other theoretical construction. (Special Relativity is an incomplete theory that was developed a decade later with the more general General Relativity).

Chemists are restricted in their use of QED due to complexity, in the same way that aerodynamicists are restricted in their use of the full Navier-Stokes fluid mechanics equations: they are fiendishly complex to handle mathematically for any other than the most simple problems.

Cheers Nihilo!

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