Fig. 4: Vertical electronic spectrum of the NV− center.
From: Accurate and convergent energetics of color centers by wavefunction theory
In the plot, computational results of MODEL-4 are presented at SA(5+8)-CASSCF(6e,4o)-NEVPT2/cc-pVDZ level of theory at the geometry of the ground state (\({(1)}^{3}{\bar{A}}_{2}\) and \({(1)}^{1}\bar{E}\) for triplets and singlets, respectively). Red arrows indicate experimentally characterized transitions. Red numbers by their side are the calculated vertical energy differences, while in parentheses are the experimental ones; the starred values are adiabatic. Black frames show the composition of electronic states, expressed in the basis of pure (group-theory) configurations presented in Fig. 1. Determinants with weights over 1% in the CASSCF wavefunction are provided, and the most simple wavefunction representations are shown, taking into account that a1 and \({a}_{1}^{* }\) molecular orbitals can be arbitrarily combined at C3v symmetry.
