Publication: ------------ Input data and extracted results for PRX accepted pre-print, Dynamical response of noncollinear spin systems at constrained magnetic moments Miquel Royo and Massimiliano Stengel DOI: https://doi.org/10.1103/c68v-8tkb Abstract: --------- Noncollinear magnets are notoriously difficult to describe within first-principles approaches based on density-functional theory (DFT) because of the presence of low-lying spin excitations. At the level of ground-state calculations, several methods exist to constrain the magnetic moments to a predetermined configuration, and thereby accelerate convergence towards self-consistency. Their use in a perturbative context, however, remains very limited. Here we present a general methodological framework to achieve parametric control over the local spin moments at the linear-response level. Our strategy builds on the concept of Legendre transform to switch between various flavors of magnetic functionals, and to relate their second derivatives via simple linear-algebra operations. Thereby, we can address an arbitrary response function at the time-dependent DFT level of theory with optimal accuracy and minimal computational effort. In the low frequency limit, we identify the leading correction to the existing adiabatic formulation of the problem [S. Ren , Phys. Rev. X 14, 011041 (2024)], consisting in a renormalization of the phonon and magnon masses due to electron inertia. As a demonstration, we apply our methodology to the THz optical response of bulk CrI3 and Cr2O3, where we identify contributions from hybrid (electro)magnons with mixed spin-lattice character. Description of uploaded tar.gz archive: ---------------------------------------------------------------- This archive contains the input and output data files used to produce the results reported in the associated manuscript for both CrI₃ and Cr₂O₃. All calculations were performed using a development version of the ABINIT code implementing the methodology described in the manuscript. The software used to generate these results is currently under active development and will be incorporated into a future public release of ABINIT. Consequently, the file formats and interfaces of the archived data may differ from those of the eventual public version of the code. In addition, due to the time lapse between the realization of the calculations for the two materials, the file formats also differ between the CrI₃ and Cr₂O₃ datasets. The supplied input and output files correspond exactly to the calculations reported in the manuscript and can be reproduced using the following development versions of ABINIT: -CrI3 calculations: commit a9f5a52b968ace2eab232050c5fe64f4aa31e965 -Cr2O3 calculations: commit 2a783529d5dbf7c968b98b32b6dcb1876569f4a5 For each material, the data are organized into two main directories: one containing ABINIT ground-state and DFPT calculations, and another containing ANADDB post-processing calculations. ABINIT directories include files for: 1. Ground-state calculations and static ddk response-function calculations. 2. DFPT calculations with constrained magnetic moments at different perturbation frequencies, including the corresponding second-order derivative database (DDB) files. 3. Berry-curvature calculations and the corresponding third-order DDB file (CrI3 only). ANADDB directories include: 1. Input DDB files obtained by merging the DDB files generated by ABINIT at different frequencies using the MRGDDB tool. 2. Input and output files for ANADDB calculations used to remove the effect of the magnetic penalty applied in the DFPT ABINIT runs, to interpolate in frequency the ensuing 2nd-order derivatives and to convert the latter to susceptibilities defined at different conditions: relaxed/fixed spins and relaxed/clamped ions. The pseudopotentials employed in the calculations are also included in a separate directory. --------------