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Abstract We present a pseudopotential-based plane-wave implementation of the rigid muffin-tin approximation (RMTA), offering a computationally efficient alternative to its traditional use in all-electron codes. The RMTA partitions the total electron-phonon coupling constant into a sum of local atomic contributions, each defined as the product of electronic and ionic factors. The former is represented by McMillan–Hopfield parameters derived from angular-momentum-resolved electron-phonon matrix elements, while the latter can be obtained from the local force matrix. Here, we derive and incorporate the electronic part of the RMTA within the widely used pseudopotential framework. We show that the McMillan–Hopfield parameters for elemental transition metals and their compounds are in excellent agreement with the results of full-potential linearized augmented plane wave calculations. Furthermore, we formulate scalable strategies for computing the ionic factors and estimate the full electron-phonon coupling constant and critical temperature. Integration of RMTA descriptors into high-throughput workflows opens a cost-effective route for screening candidate superconductors. 

Abstract The Zintl compound TlInTe₂is an intriguing material because of its outstanding thermoelectric properties at ambient pressure. Interestingly, it has recently been found that TlInTe₂exhibits a V-shape dependence of the superconducting critical temperature (T_c) under increasing pressure, which has been linked to the reversed behavior of the Raman active A_gphonon mode and anharmonic effects. In this study, we have performed first-principles calculations of the electron-phonon interactions and the superconducting properties of TlInTe₂in order to understand this unusual pressure-induced response. In contrast to experiment, we find a dome-shaped pressure-induced dependence ofT_cwith a maximum value of 0.23 K at 18 GPa, significantly lower than the experimental results. Electron doping has the potential to adjust theT_cto fall within the experimental range, but it necessitates considerably high levels of doping. Furthermore, our analysis of the phonon spectra and phonon lifetimes, including anharmonic effects, show that anharmonicity is unlikely to influence the superconducting properties of TlInTe₂. It remains an open question whether there is indeed an unusual V-shapeT_cdependence with pressure or whether the phonon-mediated theory of superconductivity used here breaks down in this system. 

Abstract Migdal-Eliashberg theory is one of the state-of-the-art methods for describing conventional superconductors from first principles. However, widely used implementations assume a constant density of states around the Fermi level, which hinders a proper description of materials with distinct features in its vicinity. Here, we present an implementation of the Migdal-Eliashberg theory within the EPW code that considers the full electronic structure and accommodates scattering processes beyond the Fermi surface. To significantly reduce computational costs, we introduce a non-uniform sampling scheme along the imaginary axis. We demonstrate the power of our implementation by applying it to the sodalite-like clathrates YH₆and CaH₆, and to the covalently-bonded H₃S and D₃S. Furthermore, we investigate the effect of maximizing the density of states at the Fermi level in doped H₃S and BaSiH₈within the full-bandwidth treatment compared to the constant-density-of-states approximation. Our findings highlight the importance of this advanced treatment in such complex materials. 

A large-scaleab initiosearch for conventional superconductors has revealed new thermodynamically stable and metastable layered metal borocarbides expected to form under ambient pressure and display critical temperatures exceeding 70 K.