hfine
Introduced in 0.99
Synopsis

Hyperfine interaction Hamiltonian.

F = hfine(System)
F = hfine(System,Spins)
Description

hfine constructs the hyperfine interaction part of the spin Hamiltonian of spin system System, that is

[eqn]

The operator matrix F is in units of MHz. If Spins is specified, it is used as an index into System for selecting spins. Spins = 1 is the first electron, follow by the other electrons, if present, and the nuclei. E.g. for a system with 3 electrons and 2 nuclei, [2 4 5] indicates the hyperfine interactions of the electron 2 with both nuclei.

Examples

For a two-spin system AB

AB = struct('S',1/2,'Nucs','23Na','g',[2 2 2],'A',[230 210 200]);
AB.Apa = [23 45 67]*pi/180;

with a hyperfine coupling matrix tilted with respect to the standard molecular frame, the eigenvalues of the hyperfine Hamiltonian are

E = eig(hfine(AB))
E =
 -270.1785
 -267.8967
 -262.5431
  146.7712
  150.1785
  157.8967
  172.5431
  173.2288

Obviously the slight anisotropy in A causes the states of the combined spin S+I to split in zero field.

See also

eeint, internal, nquad, sham, zeeman, zfield