1303.3847 (Jonathan E. Moussa)

Cubic-scaling algorithm and self-consistent mean field for random-phase
approximation with second-order screened exchange    [PDF]

Jonathan E. Moussa

The random-phase approximation with second-order screened exchange (RPA+SOSEX) is a model of electron correlation energy with two caveats: its accuracy depends on an arbitrary choice of mean field, and it scales as O(n^5) operations and O(n^3) memory for n electrons. We derive a new algorithm that reduces its scaling to O(n^3) operations and O(n^2) memory through controlled approximations and derive a self-consistent mean field that approximates Brueckner coupled-cluster doubles (BCCD) theory with RPA+SOSEX, referred to as Brueckner RPA (BRPA). The algorithm similarly reduces the scaling of second-order Moller-Plesset (MP2) perturbation theory with smaller cost prefactors than RPA+SOSEX. We test the new model's accuracy on the dissociation of H_2.

View original: http://arxiv.org/abs/1303.3847