Towards large-scale calculations with State-Specific Multireference Coupled Cluster methods: Studies on dodecane, naphthynes, and polycarbenes

Journal Article · Mon Jul 23 04:00:00 EDT 2012 · Chemical Physics Letters, 542:128-133

DOI:https://doi.org/10.1016/j.cplett.2012.05.064· OSTI ID:1047355

Brabec, Jiri; Bhaskaran-Nair, Kiran; Kowalski, Karol; Pittner, Jiri; van Dam, Hubertus JJ

Multireference Coupled Cluster (MRCC) methods are essential for accurate descriptions of molecular systems that have nearly degenerate states. A number of these methods have been developed over the last three decades but their use has been hampered by their high computational cost. The development of highly scalableMRCC codes can significantly alleviate this problem. Our recent work on the parallelization of the Brillouin-Wigner MRCC implementation has clearly demonstrated that taking advantage of large computational resources can enable the MRCC calculations on chemically relevant molecules within practical time-to-solution and memory per core constraints. In this letter we report on a parallel implementation of the Mukherjee’s state-specific MRCC model with single and double excitations (MR MkCCSD). In particular the abstraction of a methyl-group from dodecane, the singlet-triplet splitting in naphthyne isomers, and the singlet-high-spin splitting in polycarbenes are considered as demonstrations of systems with significant multireference character and of challenging size that currently can be handled with the MR MkCCSD formalism.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1047355
• Report Number(s): PNNL-SA-85744; 44892
• Journal Information: Chemical Physics Letters, 542:128-133, Journal Name: Chemical Physics Letters, 542:128-133 Vol. 542; ISSN CHPLBC; ISSN 0009-2614
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CLUSTER MODEL
COST
DODECANE
Environmental Molecular Sciences Laboratory
IMPLEMENTATION
ISOMERS
MOLECULES
multireference
Mukherjee
coupled cluster
dodecane
naphthyne
polycarbene