Abstract
Using ab initio density functional theory for superconductors (SCDFT), we systematically study the quaternary borocarbides . Treating the retarded (frequency-dependent) interaction within the random-phase approximation, we find good agreement with experiments for the calculated superconducting critical temperature in the nonmagnetic Ni- and Pd-based compounds. Replacing the density functional theory (DFT) bands with a one-shot -derived quasiparticle band structure in the SCDFT calculations further improves the agreement with experiment for several of the tested systems. We argue that the problem of accurately placing the bands within DFT, and possibly the lack of an explicit magnetic pair-breaking mechanism, explains the difficulties of SCDFT in reproducing in members of the magnetic series ( rare-earth elements with partially filled states). While the calculated is overestimated, SCDFT qualitatively captures the experimentally observed trend along the rare-earth series, which indicates that the electron-phonon couplings and dynamically screened interactions have a significant effect on .
- Received 5 October 2023
- Revised 11 March 2024
- Accepted 24 April 2024
DOI:https://doi.org/10.1103/PhysRevB.109.L180505
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