Long-range corrected double-hybrid density functionals

摘要

We extend the range of applicability of our previous long-range corrected LC hybrid functional,B97X J.-D. Chai and M. Head-Gordon, J. Chem. Phys. 128, 084106 2008, with a nonlocal description of electron correlation, inspired by second-order Moller–Plesset many-body perturbation theory. This LC “double-hybrid” density functional, denoted as B97X-2, is fully optimized both at the complete basis set limit using 2-point extrapolation from calculations using triple and quadruple zeta basis sets, and also separately using the somewhat less expensive 6-311++G 3df ,3pd basis. On independent test calculations as well as training set results,B97X-2 yields high accuracy for thermochemistry, kinetics, and noncovalent interactions. In addition, owing to its high fraction of exact Hartree–Fock exchange, B97X-2 shows significant improvement for the systems where self-interaction errors are severe, such as symmetric homonuclear radical cations.