Equation-of-motion coupled-cluster methods for doubly ionized and doubly electron-attached states with single, double, and triple substitutions: Theory, implementation, and benchmarks
We present new and computationally efficient implementation of the equation-of-motion coupled-cluster (EOM-CC) methods for doubly ionized (DIP) and doubly electron-attached (DEA) states including single, double, and triple substitutions. These methods have been implemented in the Q-CHEM package using libtensor and libxm backends. The implementation takes advantage of permutational and point-group symmetries (abelian subgroups only) and is partially spin-adapted in the case of the closed-shell references; it enables both the conventional double-precision and single-precision execution. The paper reports the programmable expressions and details of the implementation. The capabilities of the full EOM-DIP/DEA-CCSDT are demonstrated by application to methylene diradical, water, ammonia, cyclobutadiene, acetylene, ethylene, and formaldehyde. Related Research |
Funding is provided by:
 National Science Foundation |  U.S. Department of Energy |  U.S. Army Research Laboratory |  USC Dornsife College of Letters, Arts, and Sciences |
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SSC-409, University of Southern California
Los Angeles, CA 90089-0482
Phone: 213-740-4929 (Prof. Krylov), 213-740-0893 (Lab)
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