Levelpop.m

Equilibrium populations of the energy levels of a user-specified spin at the user-specified temperature. Energies are reported as fractions of kT at the temperature supplied. Note that the function is sensitive to the sign of the magnetogyric ratio (negative for electrons, positive for pro- tons, etc.). Syntax:

               [E,P,dP]=levelpop(isotope,field,temperature)

Parameters:

      isotope      - character string specifying the isotope.
                     e.g. '1H', '13C', 'E', etc.

      field        - primary magnet field in Tesla

      temperature  - spin temperature, Kelvin

Outputs:

      E            - vector of level energies

      P            - vector of level populations

      dP           - vector of level population differences