src/IntRank2/HElectronG.cc
/*
         These are SECULAR (Rotationally Invariant About Bo Field Axis)
    These Are For When The G factor Interaction Is A Perturbation To Zeeman

  The secular part of the G Hamiltonian, returned by functions in this section, 
  contain only those Hamiltonian components which explicitly commute with z-axis
  rotations (i.e. time-independent when expressed in a rotating frame). Note 
  that this Hamiltonian is field depenent since it is the electron response to
  the externally applied field.

  In more explicit mathematical terms, the Hamiltonian returned in this
  section is given by

              spins          spins                    spins
         [1]   ---   [1]      ---     G   G    G       ---   (0)
        H   =  \    H   (i) = \    [Xi * A  * T  ]   = \    H   (i)
         G     /     G        /           20   20 i    /     G
               ---            ---                      ---
                i              i                        i

   where
                    [1]       (0)           Q       Q
                   H   (i) = H   (i) = Xi  A   (i) T   (i)
                    Q         Q          i  2,0     2,0

 
   Note that this is the anisotropic G Hamiltonian in a high field limit!
   Also note that this must be ADDED to the isotropic G Hamiltonian. 

           Input                sys     : Spin system
           Output               HG0     : The secular part of the electron G
           Output               H0	: The secular part of the electron G
                                          Hamiltonian (default basis, Hz)
                                          electron G interaction
                                          for orientation {phi, theta}
                                          from the tensor PAS if set
           Note				: Also called the 1st order electron G
                                          interaction (perturbation theory)
           Note                      	: Rotationally invariant about z
	   Note				: Return is in the spin Hilbert
	  				  space of dimension 2I+1            */
These are SECULAR (Rotationally Invariant About Bo Field Axis)
These Are For When The G factor Interaction Is A Perturbation To Zeeman

The secular part of the G Hamiltonian, returned by functions in this section,
contain only those Hamiltonian components which explicitly commute with z-axis
rotations . Note
that this Hamiltonian is field depenent since it is the electron response to
the externally applied field.

In more explicit mathematical terms, the Hamiltonian returned in this
section is given by





Note that this is the anisotropic G Hamiltonian in a high field limit.
Also note that this must be ADDED to the isotropic G Hamiltonian.


These are SECULAR ( Rotationally Invariant About Bo Field Axis ) These Are For When The G factor Interaction Is A Perturbation To Zeeman The secular part of the G Hamiltonian returned by functions in this section contain only those Hamiltonian components which explicitly commute with z - axis rotations . Note that this Hamiltonian is field depenent since it is the electron response to the externally applied field . In more explicit mathematical terms the Hamiltonian returned in this section is given by Note that this is the anisotropic G Hamiltonian in a high field limit . Also note that this must be ADDED to the isotropic G Hamiltonian .
gen_op HG0(const solid_sys& sys)
  {
  int ns = sys.spins();                         
  std::vector<int> HSs = sys.HSvect();               
  matrix H;                                     
  IntG G;					
  double Om;					
  for(int i=0; i<ns; i++)			
    {
    G = sys.getGInt(i);				
    Om = sys.Omega(i)*1.e-3;			
    }
  return gen_op(H);
  }
gen_op HG0 ( const solid_sys & sys ) { int ns = sys . spins ( ) ; std :: vector < int > HSs = sys . HSvect ( ) ; matrix H ; IntG G ; double Om ; for ( int i = 0 ; i < ns ; i ++ ) { G = sys . getGInt ( i ) ; Om = sys . Omega ( i ) * 1.e-3 ; } return gen_op ( H ) ; }
These are SECULAR (Rotationally Invariant About Bo Field Axis)
These Are For When The G factor Interaction Is A Perturbation To Zeeman
These are SECULAR ( Rotationally Invariant About Bo Field Axis ) These Are For When The G factor Interaction Is A Perturbation To Zeeman
// Number of spins // Array of spin Hilbert spaces // Hamiltonian matrix // Electron G interaction // For field term // Loop over all spins //    Get electron G interact. //    Larmor frequency (GHz) // sosi - this is not yet done (I must have lost something) //    H += G.H0(HSs, i, Om);			//    Add spin pair H component