Suppose a laser is used to excite electronic transitions in potassium from the $3p$ orbitals to ones higher than $4s$. When I attempt to use the Bohr model to calculate binding energies, what I obtain for $n\le4$ disagrees significantly with this source, calling into doubt my results for $n>4$. I think it might be possible to use the Rydberg formula, but I'm having trouble finding a working example that computes the right energies; in addition, there is another form, and the two seem inconsistent. How does one calculate the binding and transition energies in potassium for levels $n>4$? Are the quantum defects for arbitrary elements available online?
What changes here if we're talking not about pure potassium but potassium chloride?