TY - JOUR
T1 - Multi-reference weak pairs local configuration interaction
T2 - Efficient calculations of bond breaking
AU - Walter, Derek
AU - Carter, Emily A.
N1 - Funding Information:
D.W. acknowledges Niri Govind, Stuart Watson, Thorsten Kluener, and Frank Starrost for illuminating discussions and technical assistance. D.W. also thanks Wlodiszlaw Duch for providing a copy of his SGGA-CI program for benchmarking purposes. This work was supported by the National Science Foundation via grant #CHE-9970033 to E.A.C. and via a graduate research fellowship to D.W.
PY - 2001/9/28
Y1 - 2001/9/28
N2 - We present a new local multi-reference singles and doubles configuration interaction (MRSDCI) algorithm. The method presented here eliminates configurations if they involve simultaneous excitations out of widely separated internal orbitals and is therefore based on the weak pairs approximation of Saebø and Pulay. Although the resulting truncated CI expansions have only about 50% as many CSFs as the non-local MRSDCI, we show that they can recover over 99% of the correlation energy. Additionally, we show for the first time that they can accurately describe bond dissociation.
AB - We present a new local multi-reference singles and doubles configuration interaction (MRSDCI) algorithm. The method presented here eliminates configurations if they involve simultaneous excitations out of widely separated internal orbitals and is therefore based on the weak pairs approximation of Saebø and Pulay. Although the resulting truncated CI expansions have only about 50% as many CSFs as the non-local MRSDCI, we show that they can recover over 99% of the correlation energy. Additionally, we show for the first time that they can accurately describe bond dissociation.
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U2 - 10.1016/S0009-2614(01)00966-6
DO - 10.1016/S0009-2614(01)00966-6
M3 - Article
AN - SCOPUS:0035965169
SN - 0009-2614
VL - 346
SP - 177
EP - 185
JO - Chemical Physics Letters
JF - Chemical Physics Letters
IS - 1-2
ER -