// The gyromagnetic ratios defined for different atom types.

    gamma_H    2.675198e4
    gamma_N    2.7116e3    // note that this should be negative: we take this into account in the sign of Da.
    gamma_C    6.7283e3
    gamma_P    1.0841e4

// canonical bond distances used for RDC scaling
// atomA-atomB    distance
    N(i)-HN(i)     1.042   
    CA(i)-HA(i)    1.119   
    C(i)-N(i+1)    1.329   
    C(i)-HN(i+1)   2.069   
    CA(i)-C(i)     1.525   
    CA(i)-CB(i)    1.525   
    CA(i)-HN(i+1)  2.560   
    CB(i)-HB(i)    1.080   
    N(i)-C(i)      2.461   
    N(i)-CA(i)     1.458   
    CA(i)-N(i+1)   2.425   
    CA(i)-HN(i)    2.117   
    C(i)-HA(i)     2.144   

