Hello everyone, I'm having a really confusing time trying to get my head around these concepts, so I will try to explain what I can... So, in proton NMR we have nuclei that can be in either spin-up or spin-down states. Nuclei align with an external magnetic field but precess. (This precession is more towards the z axis?). Applying a second, othogonal magnetic field at the precession frequency (Larmor), will cause the precession to go in the xy plane (Im not too sure about this either - sort of like a spinning top completely on its side if i can visualise it). When this happens, the nuclei can switch between states. Because of the small difference in states (Boltzmann), this can be seen via absorption at a particular RF. So is spin-lattice relaxation when the precessing goes from xy plane (spinning top on it side) to the z plane (spinning top is now perpendicular to the surface)? And where does spin-spin relaxation fit into this - from what I understand, its when spins of different nuclei don't correspond to each other. How is this different to T1 relaxation? Thanks for any help!