Could someone explain to me why the Bohr model was not able to explain the spectrum of multi-electrons atoms? I though we just need to add more stuff to it (more quantum numbers...). i tried and it gives me not so bad answer for Helium (neutral). At least without using the other quantum numbers I was able to calculate the ground-state energy of neutral Helium...It is wrong because it does not have the other quantum numbers...? Can we find a way to improve the Bohr model, or we have to totally make a new model?