RPA(D) and HRPA(D): calculation of carbon–carbon spin–spin coupling constants for saturated cycloalkanes

This study investigates the performance of two approximations to the popular second-order polarization propagator approximation (SOPPA), the doubles-corrected methods RPA(D) and HRPA(D), in calculating carbon–carbon spin–spin coupling constants (SSCCs) in 39 saturated carbocycles, totalling 188 unique coupling constants. RPA(D) scales an order below SOPPA in computational complexity while HRPA(D) differs from SOPPA in the leading coefficient. These methods may therefore prove beneficial in predictions of coupling constants of large molecules. It was found that HRPA(D) performs similarly to SOPPA in terms of accuracy for all coupling constants as well as significantly improves on RPA(D). With a roughly 55% reduction in computation time from SOPPA to HRPA(D), the latter shows great promise for the calculation of nuclear indirect carbon–carbon SSCCs in saturated carbocycles.