Nested Variant of the Method of Moments of Coupled Cluster Equations for Vertical Excitation Energies and Excited-state Potential Energy Surfaces

Journal Article · Thu May 21 00:00:00 EDT 2009 · Journal of Chemical Physics, 130(19):Art. No. 194110

DOI:https://doi.org/10.1063/1.3132592· OSTI ID:958460

Kowalski, Karol

In this article we discuss a problem of proper balancing of the non-iterative corrections to the ground- and excited-state energies obtained with approximate coupled cluster (CC) and Equation-of-Motion CC (EOMCC) approaches. It is demonstrated that for a class of excited states dominated by single excitations and for states with medium doubly excited component the newly introduced embedded variant of the Method of Moments of Coupled Cluster equations provides mathematically rigorous way of balancing the ground- and excited-state correlation effects. The resulting noniterative methodology accounting for the effect of triples (Em-EOMCCSD(T)) is tested using its parallel implementation on the systems for which iterative CC/EOMCC calculations with full inclusion of triply excited configurations or their most important subset is numerically feasible.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 958460
• Report Number(s): PNNL-SA-64359; JCPSA6; TRN: US201002%%43
• Journal Information: Journal of Chemical Physics, 130(19):Art. No. 194110, Vol. 130, Issue 19; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

97 MATHEMATICAL METHODS AND COMPUTING
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
EXCITATION
EXCITED STATES
IMPLEMENTATION
POTENTIAL ENERGY
GROUND STATES
CORRECTIONS
EQUATIONS OF MOTION
CALCULATION METHODS
coupled cluster equations
excited-state energies
Equation-of-Motion CC (EOMCC)