Preferred Label : spin-flip method;
IUPAC acronym : MP2; SF; SCF; CCSD;
IUPAC definition : Quantum mechanical method for the calculation of open-shell excited states. The method
accurately describes low-lying multi-configurational electronic states of diradicals
and triradicals in an efficient and robust single-reference scheme. The target low-spin
states (e.g., S 0 or S 1/2) are described as spin-flipping excitations (S 1)
from a well-behaved high-spin reference state (e.g., S 1 or S 3/4). By employing
theoretical models of increasing complexity for the reference (e.g., SCF, MP2, CCSD),
the accuracy in the target states’ description can be systematically improved. The
SF methods result in multistate single-step computational schemes, e.g., several low-lying
states can be computed in a single calculation that includes both dynamical and non-dynamical
correlation effects.;
Origin ID : ST07481;
Automatic exact mappings (from CISMeF team)
- See also
Quantum mechanical method for the calculation of open-shell excited states. The method
accurately describes low-lying multi-configurational electronic states of diradicals
and triradicals in an efficient and robust single-reference scheme. The target low-spin
states (e.g., S 0 or S 1/2) are described as spin-flipping excitations (S 1)
from a well-behaved high-spin reference state (e.g., S 1 or S 3/4). By employing
theoretical models of increasing complexity for the reference (e.g., SCF, MP2, CCSD),
the accuracy in the target states’ description can be systematically improved. The
SF methods result in multistate single-step computational schemes, e.g., several low-lying
states can be computed in a single calculation that includes both dynamical and non-dynamical
correlation effects.
