Complex-scaled multireference configuration-interaction method to study Be and Be-like cations' (B, C, N, O, Mg) Auger resonances $1s2s^{2}2p$ ${}^{1,3}{P}^{\mathrm{o}}$

A complex-scaled multireference configuration interaction method (CMR-CI) is proposed, which employs the multireference orbitals optimized with complex-scaled multiconfiguration self-consistent field for the specific state. First applications for the 1$s$2$s^2$2$p$ ${}^{1,3}$$P^{\mathrm{o}}$ Auger resonances of Be and Be-like cations (B, C, N, O, Mg) show that present results agree very well with the available experimental and theoretical results. For example, our CMR-CI 1$s$2$s^2$2$p$ ${}^1{P}^{\mathrm{o}}$ resonance position and linewidth for C${}^{2+}$ are (294.031 eV, 61.5 meV), which is in excellent agreement with the high-resolution advanced light source latest experiment result (293.94 $\pm$ 0.03 eV, 65 $\pm$ 12 meV) [Scully et al., J. Phys. B 38, 1967 (2005)]. Our calculations show that this CMR-CI method is a practical and important tool to study resonant states.

Figure 1

“$\theta$ trajectories” ($\alpha$ $=$ 1.00) for 1$s$2$s^2$2$p$ ${}^{1,3}$$P^{\mathrm{o}}$ Auger resonance energies for Be and Mg${}^{8+}$. $\theta$ deceases from top to down, $\theta$ step length is 0.01 radian, and $\theta$${}_0$ indicates the stationary point or resonance. The ground energy for Be and Mg${}^{8+}$ are $-$14.6168488 a.u. and $-$161.9901311 a.u., respectively.