Wave-function inspired density functional applied to the H2/H+2 challenge
In this work, we derive a new correlation functional from the Bethe-Goldstone equation. The functional is relatively simple (of MP2 complexity), but captures static correlation effects as manifested by degenerate states. We think that this functional has great potential for the development of a new class of functionals that work for static correlation. You can find more details about the work in our paper New J. Phys. 18, 073026 (2016) or online http://iopscience.iop.org/article/10.1088/1367-2630/18/7/073026/meta.
H2 (A) and H2+ (B) dissociation curves without breaking spin symmetry. Our new functional (BGE2) dissociates both H2 and H2+ correctly.