Using quantum mechanics to provide plasma chemistries

Quantum mechanics in principle provides a theory of everything, at least at the atomic and molecular scale. Or to quote Paul Dirac (1929) "The underlying physical laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known, and the difficulty is only that the exact application of these laws leads to equations much too complicated to be soluble". While Dirac's statement remains true, the rise of computers means that acceptable results can now be obtained for problems of practical interest by numerical solution of the Shrodinger equation. As a result, theory (or computation) has become the major provider of atomic and molecular data for plasma models [1]. My talk will describe my journey from predicting the specrtum of H₃⁺ which led to its detection in Jupiter's ionosphere [2], to performing relatively simple electron collision calculation on small molecules [3], to the foundation of Quantemol Ltd., to the construction of databases and chemistries which are being used to underpin research in areas ranging from technological plasmas [4] to exoplanets [5,6], to using machine learning to fill in the gaps [7]. I will end with thoughts on what the future might hold both in terms of what needs to be done better and what may be achievable in the near to medium term.