Mester, Dávid and Kállay, Mihály (2026) Accurate Core-Level Ionization Energies from an Affordable Second-Order Approach. JOURNAL OF CHEMICAL THEORY AND COMPUTATION, 22 (7). pp. 3431-3442. ISSN 1549-9618
|
Text
ct6c00015.pdf - Published Version Available under License Creative Commons Attribution. Download (2MB) | Preview |
Abstract
An approach is proposed for the accurate calculation of core-level ionization potentials (IPs) using second-order methods. The assessed theoretical frameworks are based on the iterative second-order algebraic-diagrammatic construction [ADC(2)] and configuration interaction singles with perturbative second-order correction [CIS(D)] methods. Here, our efficient implementations of IP-ADC(2) and IP-CIS(D) [] are combined with the core-valence separation (CVS) approximation, thereby enabling ionization from the core region. The approaches exhibit highly favorable scaling behavior: the computational cost is practically cubic, with only a mild prefactor that depends on the number of active core orbitals. Furthermore, the resulting wave function-based methods are combined with spin-scaling techniques and successfully extended to double-hybrid (DH) functionals without any necessary modifications in the implementation of the second-order corrections. The performance of the proposed methods was thoroughly assessed in benchmark calculations. Our results demonstrate that the iterative treatment of double excitations is essential, underscoring the necessity of the more advanced DH ansatz. Moreover, the SOS0-PBE0-2/CVS-IP-ADC(2) approach is highly competitive with more expensive higher-level coupled-cluster methods. Finally, the second-order correction introduces only a negligible overhead in the overall computational time-only about 1 min for a 61-atom azafullerene molecule using triple-zeta basis sets-thereby enabling accurate calculations for extended molecular systems.
| Item Type: | Article |
|---|---|
| Additional Information: | This work was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences (BO/00306/24) and the NKKP Starting Grant (No. 152289) of the Ministry for Culture and Innovation from the source of the National Research, Development, and Innovation Fund (NRDI). The research reported in this paper is part of project BME-EGA-02, implemented with the support provided by the NRDI, financed under the TKP2021 funding scheme. The Hungarian Governmental Information-Technology Development Agency is acknowledged for awarding access to the Komondor and the LEONARDO supercomputer, owned by the EuroHPC Joint Undertaking, hosted by CINECA (Italy) and the LEONARDO consortium. |
| Uncontrolled Keywords: | DENSITY-FUNCTIONAL THEORY; Chemistry, Physical; RAY-ABSORPTION SPECTRA; GAUSSIAN-BASIS SETS; CORRELATED MOLECULAR CALCULATIONS; EXCITED ELECTRONIC STATES; COUPLED-CLUSTER METHOD; GENERALIZED-GRADIENT-APPROXIMATION; STATE REPRESENTATION APPROACH; DIAGRAMMATIC CONSTRUCTION SCHEME; |
| Subjects: | Q Science / természettudomány > QD Chemistry / kémia |
| SWORD Depositor: | MTMT SWORD |
| Depositing User: | MTMT SWORD |
| Date Deposited: | 10 Sep 2026 08:07 |
| Last Modified: | 10 Sep 2026 08:07 |
| URI: | https://real.mtak.hu/id/eprint/246004 |
Actions (login required)
 |
View Item |
