We introduce an improved variant of the C7 pulse-sequence for efficient recoupling of spin-$\text{1/2}$ pair dipolar interactions in magic-angle spinning solid-state NMR spectroscopy. The tolerance of C7 toward isotropic as well as anisotropic chemical shift offsets and rf inhomogeneity is improved considerably by replacing the original basic element $C_{\phi }^{\text{44̄}}{\text{=(2π)}}_{\phi }{\text{(2π)}}_{\mathrm{\phi +\pi }}$ with the cyclically permuted element $C_{\phi }^{\text{14̄3}}{\text{=(π/2)}}_{\phi }{\text{(2π)}}_{\mathrm{\phi +\pi }}{\text{(3π/2)}}_{\phi }.$ The improved performance of this permutationally offset stabilized variant of C7 is analyzed by average Hamiltonian theory to fifth order, numerical simulations, and demonstrated by experiments on powder samples of doubly ${}^{13}\mathrm{C}$ -labeled barium oxalate hemihydrate and diammonium fumarate.

We describe an efficient method for the recovery of homonuclear dipole–dipole interactions in magic‐angle spinning NMR. Double‐quantum homonuclear rotary resonance (2Q‐HORROR) is established by fulfilling the condition ω_r=2ω₁, where ω_r is the sample rotation frequency and ω₁ is the nutation frequency around an applied resonant radio frequency (rf) field. This resonance can be used for double‐quantum filtering and measurement of homonuclear dipolar interactions in the presence of magic‐angle spinning. The spin dynamics depend only weakly on crystallite orientation allowing good performance for powder samples. Chemical shift effects are suppressed to zeroth order. The method is demonstrated for singly and doubly ¹³C labeled L‐alanine.