Fig. 3: Vertical excitation energies w.r.t. inverse model size.
From: Accurate and convergent energetics of color centers by wavefunction theory
Energies of the \({(1)}^{1}\bar{E}\), \({(1)}^{1}{\bar{A}}_{1}\), and \({(1)}^{3}\bar{E}\) states obtained for different choices of active space and basis set are visualized in (a–c), respectively, based on data from Supplementary Tables 2 and 3. The CASSCF-level and the NEVPT2 corrected results for the (6e,4o) active space are presented in blue and red, respectively. The symbol and the hue vary with the choice of basis set (cc-pVDZ, cc-pVTZ, cc-pVQZ, as well as CBS extrapolation based on cc-pV{D,T}Z data); the colored lines serve as a guide to the eye. The results for the (12e,7o) and (10e,6o) alternative active spaces of MODEL-3, discussed in Supplementary Note 3, are in green and orange, respectively. (The color code is the same for all subplots.) Shaded areas demonstrate a 0.1 eV energy tolerance around CASSCF(6,4)-based MODEL-4 results estimated at the CBS limit. Vertical black dashed lines indicate the position of MODEL-1, 2, 3, and 4 in the inverse system size scale.
