Related papers: Hylleraas-configuration-interaction analysis of th…
The existence of the $0_3^+$ and $0_4^+$ states around 10 MeV excitation energy in ${^{12}{\rm C}}$ is confirmed by a fully microscopic 3$\alpha$ cluster model. Firstly, a GCM (generator coordinate method) calculation is performed by…
The \textit{ab initio} approach is used to evaluate the excitation energies of the $2s2p \, ^{2S+1}P_J$ states from the ground state as well as the $2s2p \, ^3P_1 \rightarrow 2s2p \, ^3P_0$ and $2s2p \, ^3P_2 \rightarrow 2s2p \, ^3P_1$…
The theory of the long-range interaction of metastable excited atomic states with ground-state atoms is analyzed. We show that the long-range interaction is essentially modified when quasi-degenerate states are available for virtual…
Striving to define very accurate vertical transition energies, we perform both high-level coupled cluster (CC) calculations (up to CCSDTQP) and selected configuration interaction (sCI) calculations (up to several millions of determinants)…
We calculate excitation energies for low states of nobelium, including states with open $5f$ subshell. An efficient version of the many-electron configuration-interaction method for treating the atom as a sixteen external electrons system…
We present a method which computes many-electron energies and eigenfunctions by a full configuration interaction which uses a basis of atomistic tight-binding wave functions. This approach captures electron correlation as well as atomistic…
We show in this note how many electron irreducible representations of the Lorentz group L can be expressed in terms of the sums of Slater determinants and principal minors. In this way the full configuration wave function of quantum…
Accurate solution of the many-electron problem including correlations remains intractable except for few-electron systems. Describing interacting electrons as a superposition of independent electron configurations results in an apparent…
Helium (He) is the ideal atom to perform tests of ab-initio calculations in two-electron systems that consider all known effects, including quantum-electrodynamics and nuclear-size contributions. Recent state-of-the-art calculations and…
We have performed large-scale configuration interaction (CI) calculations using CIV3for the lowest (in energy) 155 fine-structure levels of aluminum-like germanium ion. We have calculated the energy levels, lifetimes, oscillator strengths,…
In this work, trions in two-dimensional (2D) space are studied by variational method with trial wavefunctions being constructed by linear combinations of 2D slater-type orbitals (STOs). Via this method, trion energy levels and wavefunctions…
We extend the CIPSI-driven CC($P$;$Q$) methodology [K. Gururangan et al., J. Chem. Phys. 155 (2021) 174114], in which the leading higher-than-doubly excited determinants are identified using the selected configuration interaction (CI)…
By combining extrapolated selected configuration interaction (sCI) energies obtained with the CIPSI (Configuration Interaction using a Perturbative Selection made Iteratively) algorithm with the recently proposed short-range…
We present high-precision non-relativistic variational calculations of bound vibrational-rotational state energies for the $H_2^+$ and $D_2^+$ molecular ions in each of the lowest electronic states of $\Sigma_g$, $\Sigma_u$, and $\Pi_u$…
Using the multiconfiguration Dirac-Hartree-Fock and the relativistic configuration interaction methods, a consistent set of transition energies and radiative transition data for the lowest 546 (623, 701, 745) states of the $3p^4 3d$, $3s…
Recently, a new distributed implementation of the full configuration interaction (FCI) method has been reported [Gao et al. J. Chem Theory Comput. 2024, 20, 1185]. Thanks to a hybrid parallelization scheme, the authors were able to compute…
Energies of ns[1/2] (n= 6-9), np[j] (n = 6-8), nd[j] (n= 6-7), and 5f[j] states in neutral Au and Au-like ions with nuclear charges Z = 80 - 83 are calculated using relativistic many-body perturbation theory. Reduced matrix elements,…
Five physics mechanisms of interaction leading to the binding of the ${\rm H}_3^+$ molecular ion are identified. They are realized in a form of variational trial functions and their respective total energies are calculated. Each of them…
Calculations of the lowest valence {\pi}* as well as the 3s and higher energy 3p{\sigma} Rydberg excited states of the CO2 molecule are carried out using density functionals with variational optimization of the orbitals, an approach…
The fully relativistic multiconfiguration Dirac--Hartree--Fock method is used to compute excitation energies and lifetimes for the 143 lowest states of the $3s^23p^3$, $3s3p^4$, $3s^23p^23d$, $3s3p^33d$, $3p^5$, $3s^23p3d^2$ configurations…