The tensor hypercontracted parametric reduced density matrix algorithm: Coupled-cluster accuracy with O(r4) scaling
Neil Shenvi, Helen van Aggelen, Yang Yang, and Weitao Yang. The Tensor Hypercontracted Parametric Reduced Density Matrix Algorithm: Coupled-Cluster Accuracy With O(r4) Scaling. Vol. 139, no. 5, J. Chem. Phys., 2013, p. 054110.