Convergence of attenuated second order Møller–Plesset perturbation theory towards the complete basis set limit

Attenuated second order Møller–Plesset theory (MP2) is parameterized for noncovalent interactions using basis sets that range as high as augmented triple (T) and quadruple (Q) zeta with T→Q extrapolation towards the complete basis set (CBS) limit. By comparing training and testing performance as a function of basis set size, the effectiveness of attenuation as a function of basis set can be assessed. While attenuated MP2 with T→Q extrapolation improves systematically over MP2, there are at most small improvements over attenuated MP2 in the aug-cc-pVTZ basis. Augmented functions are crucial for the success of attenuated MP2.