Doubly excited3Se,3De and3Ge states of two-electron atomic systems

Density-functional calculations for doubly excited states of He, and

“…results agree well with the pseudopotential Feshbach result of Bachau et al (1991). 4s5s levels of Z > 2 are reported only by Das et al (1994) using a time-dependent variationperturbation (TDVP) method and, in general, they are close to our results. The errors in the total energy values for the atom with lowest Z are the highest while the errors go down with an increase in the nuclear charge Z.…”

“…e Conneely and Lipsky (1978). f Ho (1989) as quoted in h. g Shearer-Izumi (1977) as quoted in h. h Das et al (1994). i Bachau et al (1991).…”

Modified Atomic Orbital Calculations for $(1s,nl)^3L^{\pi}$ and $_2 (1,0)_n^{±1,3}S^e$ Excited States of He Isoelectronic Sequence

“…In Table 8, the present calculations for excitation energies of 2 (1,0) 3 +1 S e and 2 (1,0) 3 −3 S e autoionizing states of the helium atom are compared to various ab initio calculations such as the complex-coordinates method used by Burgers et al [22] and by Ho [15], the hyperspherical coordinate approaches employed by Koyama et al [23], the truncateddiagonalization method utilized by Conneely and Lipsky [10], the time-dependent variation perturbation theory applied by Ray and Mukherjee [24] and by Das et al [27], the discretization technique used by Macias and Riera [13], the multiconfiguration calculation employed by Lipsky et al [26] and with the many-body perturbation theory to all orders of electron-electron interaction applied by Lindroth [25]. The agreement for the 2 (1,0) 3 +1 S e energy level of He with the result of Burgers et al [29] is seen to be excellent.…”