Discovering Unknown Gases: Using Quantum Numbers for Spectrum Analysis

[MonsieurWise]

Uhm...I'm doing some experiment with some unknown gas tubes. I have a spectrum when I use the grating. Can I, by some ways, use the quantum numbers to identify what the gas inside is...? I've heard of one method, but I could not find the name. Thank you in advance.

 

[Dr Transport]

In principle you can, if you can find out the whether or not it is an atomic species or diatomic species you should be able to figure out the gas...

 

[MonsieurWise]

Oh yeah, I used only atomic species (like just Lithium gas or hydrogen gas, is that what u mean...?). Is there a way I can identify the mystery gas?
The way I'm trying right now is to use the equation 1/lambda = RZ^2 (1/n_f + 1/n_i), play around with the numbers to guest n_f and n_i, plot the points on a graph, with (1/n_f + 1/n_i) on the x-axis and (1/lambda) for y-axis. The linear best fit line should give me a slope of RZ^2, and that would be how I find Z, thus the element.
However, I found this method is way too simple and I can just apply it to small atoms, such as Hydrogen or Helium. For big atom like Oxygen...well, I failed miserably. I searched but find no other methods to include the others quantum numbers into calculation. Could you show me a website that introduce the method?
this is the first time I've done anything with Quantum Physics...sorry if my questions seems stupid...
Thank you very much!