Abstract.
The iterative difference-dedicated CI method (IDDCI) has been applied to determine excitation energies in small systems for which benchmark FCI and other high-level calculations exist. Transitions to excited singlet and triplet states in Be and vertical transitions in CH+, BH and CH2 are reported. The deviations from FCI results are lower than 0.1 eV and compare advantageously with SDCI including size-consistency corrections, (SC)2SDCI, and with coupled cluster calculations including the effect of triples, especially for the states which have a predominant double excitation character. The IDDCI procedure has been speeded up by using smaller subspaces for optimizing the molecular orbitals.
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Received: 17 January 1997 / Accepted: 31 July 1997
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García, V., Reguero, M. & Caballol, R. Application of the iterative difference-dedicated configuration interaction method to the determination of excitation energies in some benchmark systems: Be, CH+, BH and CH2. Theor Chem Acc 98, 50–56 (1997). https://doi.org/10.1007/s002140050277
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DOI: https://doi.org/10.1007/s002140050277