Input data format: { } = optional, [ ] = it depends, # = comment Structure of the input data: =============================================================================== &INPUTHP ... / 'pwscf' Prepended to input/output filenames; must be the same used in the calculation of unperturbed system. value of the ESPRESSO_TMPDIR environment variable if set;
current directory ('./') otherwise Directory containing input, output, and scratch files; must be the same as specified in the calculation of the unperturbed system. 1 = 1 : minimal output = 2 : as above + symmetry matrices, final response matrices chi0 and chi1 and their inverse matrices, full U matrix = 3 : as above + various detailed info about the NSCF calculation at k and k+q = 4 : as above + response occupation matrices at every iteration and for every q point in the star 1.d7 Maximum allowed run time before the job stops smoothly. 1,1,1 Parameters of the Monkhorst-Pack grid (no offset). Same meaning as for nk1, nk2, nk3 in the input of pw.x. .false. If .true. then the HP code will skip the equivalence analysis of q points, and thus the full grid of q points will be used. Otherwise the symmetry is used to determine equivalent q points (star of q), and then perform calculations only for inequivalent q points. .false. find_atpert If .true. determines the number of perturbations (i.e. which atoms will be perturbed) and exits smoothly without performing any calculation. For DFT+U+V, it also determines the indices of inter-site couples. .false. perturb_only_atom If .true. determines the number of q points for a given perturbed atom and exits smoothly. This keyword can be used only if perturb_only_atom is set to .true. 1 Method for searching of atoms which must be perturbed. 1 = Find how many inequivalent Hubbard atoms there are by analyzing unperturbed occupations. 2 = Find how many Hubbard atoms to perturb based on how many different Hubbard atomic types there are. Warning: atoms which have the same type but which are inequivalent by symmetry or which have different occupations will not be distinguished in this case (use option 1 or 3 instead). 3 = Find how many inequivalent Hubbard atoms there are using symmetry. Atoms which have the same type but are not equivalent by symmetry will be distinguished in this case. 4 = Perturb all Hubbard atoms (the most expensive option) 5.D-5 Threshold for a comparison of unperturbed occupations which is needed for the selection of atoms which must be perturbed. Can be used only when find_atpert = 1. skip_type(i) = .false. equiv_type skip_type(i), where i runs over types of atoms. If skip_type(i)=.true. then no linear-response calculation will be performed for the i-th atomic type: in this case equiv_type(i) must be specified, otherwise the HP code will stop. This option is useful if the system has atoms of the same type but opposite spin pollarizations (anti-ferromagnetic case). This keyword cannot be used when find_atpert = 1. equiv_type(i) = 0 skip_type equiv_type(i), where i runs over types of atoms. equiv_type(i)=j, will make type i equivalent to type j (useful when nspin=2). Such a merging of types is done only at the post-processing stage. This keyword cannot be used when find_atpert = 1. perturb_only_atom(i) = .false. compute_hp If perturb_only_atom(i)=.true. then only the i-th atom will be perturbed and considered in the run. This variable is useful when one wants to split the whole calculation on parts. Note: this variable has a higher priority than skip_type. 1 last_q, sum_pertq Computes only the q points from start_q to last_q. IMPORTANT: start_q must be smaller or equal to the total number of q points found. number of q points start_q, sum_pertq Computes only the q points from start_q to last_q. IMPORTANT: last_q must be smaller or equal to the total number of q points found. .false. start_q, last_q, perturb_only_atom If it is set to .true. then the HP code will collect pieces of the response occupation matrices for all q points. This variable should be used only when start_q, last_q and perturb_only_atom are used. .false. perturb_only_atom If it is set to .true. then the HP code will collect pieces of the chi0 and chi matrices (which must have been produced in previous runs) and then compute Hubbard parameters. The HP code will look for files tmp_dir/HP/prefix.chi.i.dat. Note that all files prefix.chi.i.dat (where i runs over all perturbed atoms) must be placed in one folder tmp_dir/HP/. compute_hp=.true. must be used only when the calculation was parallelized over perturbations. 1.D-5 Convergence threshold for the response function chi, which is defined as a trace of the response occupation matrix. 1.D-14 Initial threshold for the solution of the linear system (first iteration). Needed to converge the bare (non-interacting) response function chi0. The specified value will be multiplied by the number of electrons in the system. 1.D-11 Threshold for the convergence of eigenvalues during the iterative diagonalization of the Hamiltonian in the non-self-consistent-field (NSCF) calculation at k and k+q points. Note, this quantity is NOT extensive. 100 Maximum number of iterations in the iterative solution of the linear-response Kohn-Sham equations. alpha_mix(1)=0.3 Mixing parameter (for the i-th iteration) for updating the response SCF potential using the modified Broyden method. See: D.D. Johnson, PRB 38, 12807 (1988). 4 Number of iterations used in potential mixing using the modified Broyden method. See: D.D. Johnson, PRB 38, 12807 (1988). 6 Number of nearest neighbors of every Hubbard atom which will be considered when writting Hubbard V parameters to the file parameters.out, which can be used in the subsequent DFT+U+V calculation. This keyword is used only for DFT+U+V (post-processing stage). 2 Minimum value of the orbital quantum number of the Hubbard atoms starting from which (and up to the maximum l in the system) Hubbard V will be written to the file parameters.out. lmin refers to the orbital quantum number of the atom corresponding to the first site-index in Hubbard_V(:,:,:). This keyword is used only for DFT+U+V and only in the post-processing stage. Example: lmin=1 corresponds to writing to file V between e.g. oxygen (with p states) and its neighbors, and including V between transition metals (with d states) and their neighbors. Instead, when lmin=2 only the latter will be written to parameters.out. 100.D0 Maximum distance (in Bohr) between two atoms to search neighbors (used only at the postprocessing step for DFT+U+V). This keyword is useful when there are e.g. defects in the system. 6.D-4 Threshold (in Bohr) for comparing inter-atomic distances when reconstructing the missing elements of the response susceptibility in the post-processing step. .false. If .true. the metallic response term at q=0 is ignored (i.e. the last term in Eq. (22) in PRB 103, 045141 (2021)). This is useful for magnetic insulators to avoid the divergence of the calculation.