6533b7d5fe1ef96bd1263e8a
RESEARCH PRODUCT
The CCSD(T) model with Cholesky decomposition of orbital energy denominators
Henrik KochThomas Bondo PedersenBerta FernándezAlfredo Sánchez De MerásJavier López Cacheirosubject
Atomic and Molecular Physics and Opticorbital energy denominatorT-modelreduced scalingCondensed Matter PhysicCondensed Matter PhysicsAtomic and Molecular Physics and OpticsSpecific orbital energyCoupled clusterAtomic orbitalComputational chemistryDecomposition (computer science)Applied mathematicsA priori and a posterioriCCSD(T)Physical and Theoretical ChemistryCholesky decompositionScalingMathematicsCholesky decompositiondescription
A new implementation of the coupled cluster singles and doubles with approximate triples correction method [CCSD(T)] using Cholesky decomposition of the orbital energy denominators is described. The new algorithm reduces the scaling of CCSD(T) from N-7 to N-6, where N is the number of orbitals. The Cholesky decomposition is carried out using simple analytical expressions that allow us to evaluate a priori the order in which the decomposition should be carried out and to obtain the relevant parts of the vectors whenever needed in the calculation. Several benchmarks have been carried out comparing the performance of the conventional and Cholesky CCSD(T) implementations. The Cholesky implementation shows a speed-up factor larger than O-2/V, where O is the number of occupied and V the number of virtual orbitals, and in general at most 5 vectors are needed to get a precision of mu E-h. We demonstrate that the Cholesky algorithm is better suited for studying large systems. (c) 2010 Wiley Periodicals, Inc. Int J Quantum Chem 111: 349-355, 2011 (Less)
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2010-11-23 | International Journal of Quantum Chemistry |