Publication at Faculty of Science, Central Library of Charles University |
2012
Abstract
Adiabatic singlet-triplet gap of the oxyallyl diradical has been studied by multireference Brillouin-Wigner and Mukherjee's coupled cluster methods (BWCC and MkCC). The results demonstrate the necessity to include connected triples excitations, as well as employing a size-extensive MRCC method.
The best result, calculated at the MkCCSD(T-u)/cc-pVQZ level, is in an excellent agreement with both experiment and recent spin-flip EOMCCSD(dT) calculations.