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The hydrogenoid atoms and ions, with a single electron, are the exception that proves the rule, because anything more complex cannot be computed accurately.
Rather: there is no known closed-form solution (and there likely won't be any).
Rather: there is no known closed-form solution (and there likely won't be any).
There’s an intrinsic physical limit to which you can resolve a spectrum, so arbitrarily many digits of precision aren’t exactly a worthy pursuit anyway.