[Bidagdha_TADIR]

I was trying to understand the basic principle behind NMR and I learned that a nucleus has either 0, integer or half-integer spin. I saw some examples showing ¹²₆C has a spin of 0, ⁷₃Li has a spin of 3/2, ¹³₆C has a spin of 1, ¹⁴₇N has a spin of 1.

There are some general rules described to explain which nucleus will have integer value, which will have half-integer value and which will have value of 0 (this is also said in some spectroscopy books as well). But I couldn't find any link that described the calculation of the spin number of a nucleus (I really like to know how ⁷₃Li ended up with a spin number of 3/2.

Some links said that since proton and neutron both have spin of 1/2, the interaction between the two will determine the nuclear spin But I like to know how.

This is kind of a question for those who are studying quantum physics, but still since this concept is important in NMR, I am guessing some of you will know this. Thanks.

[gjuhasz]

I am sorry to disappoint you, but to answer this question is not something you can easily calculate on a piece of paper.

[Irlanur]

This is kind of a question for those who are studying quantum physics, but still since this concept is important in NMR, I am guessing some of you will know this. Thanks.

You need to know smth about nuclear structure. I don't really know anything about it, but you don't need it for NMR since the Spins for the relevant nuclei are known and can be found in tables.

[Enthalpy]

¹³C has a spin of -1/2, not 1.

To my understanding, an odd number of proton+neutron results in a half-integer spin. The details of the organisation within the nucleus (which is unknown presently) changes only integer amounts of the spin.

http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/nspin.html