def calc_NMR_Relax(J, fdd, fcsa, gammaH, gammaN):
    """
        Function to calculate the R1, R2 and NOE from the spectral densities and the physical parameters for the 
        dipole-dipole and csa contributions, fdd and fcsa. 
    """
    R1 = fdd * (J['Diff'] + 3*J['15N'] + 6*J['Sum']) + fcsa * J['15N']
    
    R2 = (0.5 * fdd * (4*J['0'] + J['Diff'] + 3*J['15N'] + 6*J['1H'] + 6*J['Sum']) 
          + (1./6.) * fcsa*(4*J['0'] + 3*J['15N']) )
    
    NOE = 1 + ((fdd*gammaH)/(gammaN*R1))*(6*J['Sum'] - J['Diff'])
    
    return R1, R2, NOE