TY - JOUR
T1 - Breaking bonds with the state-selective multireference coupled-cluster method employing the single-reference formalism
AU - Piecuch, Piotr
AU - Adamowicz, Ludwik
PY - 1995
Y1 - 1995
N2 - The state-selective (SS) multireference coupled-cluster (CC) method exploiting the single-reference (SR) formalism [P. Piecuch, N. Oliphant, and L. Adamowicz, J. Chem. Phys. 99, 1875 (1993)] is applied to BH and H2O at equilibrium and displaced geometries. Different selections of active spaces are considered. Comparison with the SR CC approaches involving single and double (CCSD), single, double, and triple (CCSDT) and single, double, triple, and quadruple (CCSDTQ) excitations, and with the full configuration interaction method, indicates remarkable stability and accuracy of the SS CC results for difficult bond breaking cases. For the first time, the ab initio SS CC calculations include the most complete SS CCSD(TQ) approximation, which emerges through selection of the most essential clusters appearing in the full SR CCSDTQ theory.
AB - The state-selective (SS) multireference coupled-cluster (CC) method exploiting the single-reference (SR) formalism [P. Piecuch, N. Oliphant, and L. Adamowicz, J. Chem. Phys. 99, 1875 (1993)] is applied to BH and H2O at equilibrium and displaced geometries. Different selections of active spaces are considered. Comparison with the SR CC approaches involving single and double (CCSD), single, double, and triple (CCSDT) and single, double, triple, and quadruple (CCSDTQ) excitations, and with the full configuration interaction method, indicates remarkable stability and accuracy of the SS CC results for difficult bond breaking cases. For the first time, the ab initio SS CC calculations include the most complete SS CCSD(TQ) approximation, which emerges through selection of the most essential clusters appearing in the full SR CCSDTQ theory.
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U2 - 10.1063/1.469156
DO - 10.1063/1.469156
M3 - Article
AN - SCOPUS:0001586684
SN - 0021-9606
VL - 102
SP - 898
EP - 904
JO - The Journal of chemical physics
JF - The Journal of chemical physics
IS - 2
ER -