7.12 Restricted Active Space Spin-Flip (RAS-SF) and Configuration Interaction (RAS-CI)

7.12.5 Diabatization of RAS-CI Eigenstates

(May 16, 2021)

Characterization of RAS-CI electronic states can be alternatively performed by diabatizaion of multiple eigenstates of the RAS-CI Hamiltonian. Diabatic states can be obtained following a Boys, 1062 Subotnik J. E. et al.
J. Chem. Phys.
(2008), 129, pp. 244101.
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Edmiston-Ruedenberg 1058 Subotnik J. E. et al.
J. Chem. Phys.
(2009), 130, pp. 234102.
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or dipole-quadrupole (DQ) 472 Hoyer C. E. et al.
J. Chem. Phys.
(2014), 141, pp. 114104.
Link
localization schemes. See section 10.15.1.2 for details. To activate the diabatization analysis of excited states in RAS-CI method it is necessary to define a section block (see $localized_diabatization keyword) that defines the list of excited states to be included in the diabatization (by increasing order). This is equivalent to the one used for the diabatization of CIS/TDDFT states.