I'm trying to teach myself the theory behind NMR spectroscopy, but I am having some trouble with some pchem/physics concepts that I have never seen before.(adsbygoogle = window.adsbygoogle || []).push({});

The chapter I am currently on talks about the quantization of nuclear angular momentum. What I don't understand is, what is the difference between spin number (I) and nuclear spin angular momentum which my book gives as

P=h/2pi (I(I+1))^1/2

I have looked up what nuclear spin number (I) means on some physics websites and they state that I is the total angular momentum of the nuclei so I don't really understand what P really is if I is the total angular momentum of the nuclei.

Another term they talk about in the chapter is quantum number m_I (is this almost the same thing as the quantum number m_s for the electron?).

Given a magnetic field of strengthB(in the z direction)a magnetic momentuwould have an energy U given by

U=-u.B=-u_zB where u_z is the z component ofu. They then go on to show that the energy is given by

U=-y(h/2pi)m_IB (y is the magnetogyric ratio) and state that there are 2I+1 values for m_I.

Could someone please explain P, I, and m_I ?? sorry for the equations, I don't know how to use latex.

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# NMR theory help

**Physics Forums | Science Articles, Homework Help, Discussion**