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Title: Communication: Application of state-specific multireference coupled cluster methods to core-level excitations

Abstract

The concept of the model space underlying multireference coupled-cluster (MRCC) formulations is a powerful tool to deal with complex correlation effects for various electronic states. Here, we demonstrate that iterative state-specific MRCC methods (SS-MRCC) based on properly defined model spaces can be used to describe core-level excited states even when canonical Hartree-Fock orbitals are utilized. We show that the SS-MRCC models with single and double excitations (SSMRCCSD) are comparable in accuracy to high-level single reference equation-of-motion coupled cluster (EOMCC) formalism. We also demonstrate that the SS-MRCC methods are capable of providing high accuracy results without experiencing numerical problems of the EOMCC methods.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1059187
Report Number(s):
PNNL-SA-90515
44892
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics, 137(17):Article No.171101
Additional Journal Information:
Journal Name: Journal of Chemical Physics, 137(17):Article No.171101
Country of Publication:
United States
Language:
English
Subject:
Multireference; coupled cluster; excitations; MRCC; electronic states; Hartree-Fock; Environmental Molecular Sciences Laboratory

Citation Formats

Brabec, Jiri, Bhaskaran-Nair, Kiran, Govind, Niranjan, Pittner, Jiri, and Kowalski, Karol. Communication: Application of state-specific multireference coupled cluster methods to core-level excitations. United States: N. p., 2012. Web. doi:10.1063/1.4764355.
Brabec, Jiri, Bhaskaran-Nair, Kiran, Govind, Niranjan, Pittner, Jiri, & Kowalski, Karol. Communication: Application of state-specific multireference coupled cluster methods to core-level excitations. United States. doi:10.1063/1.4764355.
Brabec, Jiri, Bhaskaran-Nair, Kiran, Govind, Niranjan, Pittner, Jiri, and Kowalski, Karol. Wed . "Communication: Application of state-specific multireference coupled cluster methods to core-level excitations". United States. doi:10.1063/1.4764355.
@article{osti_1059187,
title = {Communication: Application of state-specific multireference coupled cluster methods to core-level excitations},
author = {Brabec, Jiri and Bhaskaran-Nair, Kiran and Govind, Niranjan and Pittner, Jiri and Kowalski, Karol},
abstractNote = {The concept of the model space underlying multireference coupled-cluster (MRCC) formulations is a powerful tool to deal with complex correlation effects for various electronic states. Here, we demonstrate that iterative state-specific MRCC methods (SS-MRCC) based on properly defined model spaces can be used to describe core-level excited states even when canonical Hartree-Fock orbitals are utilized. We show that the SS-MRCC models with single and double excitations (SSMRCCSD) are comparable in accuracy to high-level single reference equation-of-motion coupled cluster (EOMCC) formalism. We also demonstrate that the SS-MRCC methods are capable of providing high accuracy results without experiencing numerical problems of the EOMCC methods.},
doi = {10.1063/1.4764355},
journal = {Journal of Chemical Physics, 137(17):Article No.171101},
number = ,
volume = ,
place = {United States},
year = {2012},
month = {11}
}