Spinss: Accelerating the four-state method for spin Hamiltonian via appropriate initial spin densities
Description
The four-state method [{ Phys. Rev. B , 224,429 (2011)}] is a reliable approach for calculating parameters of spin Hamiltonian in magnetic materials. However, the conventional self-consistent implementations often suffer from convergence difficulty and high computational costs. Here, we propose a method to generate appropriate initial spin densities that significantly reduces the number of the required self-consistent iterations. Remarkably, we find that this initial distribution even enables the non-self-consistent calculations to yield reasonable results. To facilitate the application of this method, we have developed Spinss, an open-source code that creates the initial spin densities and other necessary files for both self-consistent and non-self-consistent density functional theory calculations. We provide a detailed description of the algorithm, input and output files, and application examples which demonstrate the effectiveness of Spinss for both bulk and low-dimensional systems.