Relativistic quantum mechanics

{wiki}

The first really good <quantum mechanics> theory made compatible with <special relativity> was the <Dirac equation>.

And then came <quantum electrodynamics> to improve it: <Dirac equation vs quantum electrodynamics>.

TODO: does it use full blown QED, or just something intermediate?

https://www.youtube.com/watch?v=NtnsHtYYKf0 "Mercury and Relativity - Periodic Table of Videos" by <Periodic Videos> (2013). Doesn't give the key juicy details/intuition. Also mentioned on Wikipedia: https://en.wikipedia.org/wiki/Relativistic_quantum_chemistry#Mercury
