Lowest order constants in the ERHAM tunneling parameters input:

--------------------------------------------------------------------------------
  IQ1 IQ2  MEG KAP  JP  KP    ApJS2002(acetone)                   JCP1997 type
                              type notation                       notation*

                                                                  B_K,P,R_qq' 
--------------------------------------------------------------------------------

energy tunneling parameters:                                         

   q   q'   1   0   0   0     eps_qq'          eps_10,eps_01
                                               eps_11
                                               eps_20,eps_02
   q  -q'   1   0   0   0     eps_q,-q'        eps_1,-1

rotational constant tunneling parameters:
   
   q   q'   1   0   0   2     [A-(B+C)/2]_qq'                     B_020_qq'
   q   q'   1   0   2   0     [B+C]/2_qq'                         B_200_qq'
   q   q'   1   2   0   0     [B-C]/4_qq'                         B_002_qq'

centrifugal distortion constant tunneling parameters:
    
   q   q'   1   0   4   0     [Delta_J]_qq'                       B_400_qq'           
   q   q'   1   0   2   2     [Delta_JK]_qq'                      B_220_qq'           
   q   q'   1   0   0   4     [Delta_K]_qq'                       B_040_qq'           
   q   q'   1   2   2   0     [delta_J]_qq'                       B_202_qq'           
   q   q'   1   2   0   2     [delta_K]_qq'                       B_022_qq'           
   q   q'   1   4   0   0     [d_2]_qq'                           B_004_qq'           

   q   q'   1   0   6   0     [Phi_J]_qq'
   q   q'   1   0   4   2     [Phi_JK]_qq'
   q   q'   1   0   2   4     [Phi_KJ]_qq'
   q   q'   1   0   0   6     [Phi_K]_qq'
   q   q'   1   2   4   0     [phi_J]_qq'
   q   q'   1   2   2   2     [phi_JK]_qq'
   q   q'   1   2   0   4     [phi_K]_qq'

DeltaK=1 Coriolis tunneling parameters:

   q   q'  -1   0   0   1     [G_z]_qq'                          B_010_qq'
   q   q'  -1   1   0   0                                        B_001_qq'

pure rotation, S-reduction:
    
   0   0    1   2   2   0     d1=-delta_J  
   0   0    1   4   0   0     d2

   0   0    1   2   4   0     h1=phi_J
   0   0    1   4   2   0     h2
   0   0    1   6   0   0     h3
   
pure rotation octic constants, A-reduction:

   0   0    1   0   8   0     LJ     
   0   0    1   0   6   2     LJJK   
   0   0    1   0   4   4     LJK    
   0   0    1   0   2   6     LKKJ   
   0   0    1   0   0   8     LK     
   0   0    1   2   6   0     lJ     
   0   0    1   2   4   2     lJK    
   0   0    1   2   2   4     lKJ    
   0   0    1   2   0   6     lK     
      
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------

* NOTES:

q, q' indicate localised state for first and second motion resp.,
      most common combinations are (1,0) and (0,1) while the case 
      q=q'=0 declares pure rotation terms (first fifteen A-reduced 
      terms are declared explicitly in lines preceding the tunneling 
      parameter input)

K,P,R define  P^K,  Pz^P, and (P+^R + P-^R) operators

1/    In the JCP1997 paper, p.4494 l.3 of left column this notation was 
      originally suggested as B_K,P,R^KAP_qq' 

2/    Mapping with ERHAM input is K=JP, P=KP and R=KAP so that the KAP index 
      switches position by two columns to the right 
          from: IQ1 IQ2  MEG     KAP  JP  KP 
            to: B_K,P,R_qq'=  B( JP,  KP, KAP)_IQ1,IQ2
      when converting from ERHAM input/output to the B notation
      
3/    ERHASR carries out the above conversion automatically
  
4/    MEG = +1 for even order of angular momenta,  -1 for odd (MEG=omega)