HP – A code for the calculation of Hubbard parameters using density-functional perturbation theory

We introduce HP, an implementation of density-functional perturbation theory, designed to compute Hubbard parameters (on-site $U$ and inter-site $V$) in the framework DFT+$U$ DFT+$U$+$V$. The code does not require use computationally expensive supercells traditional linear-response approach; instead, unit cells are used with monochromatic perturbations that significantly reduce computational cost determining parameters. HP is open-source software distributed under terms GPL as a component Quantum ESPRESSO. As other components, optimized run on variety different platforms, from laptops massively parallel architectures, using native mathematical libraries (LAPACK FFTW) hierarchy custom parallelization layers built top MPI. effectiveness showcased by computing self-consistently for phospho-olivine Li$_x$Mn$_{1/2}$Fe$_{1/2}$PO$_4$ ($x=0, 1/2, 1$) highlighting accuracy predictions geometry Li intercalation voltages.