Searchers

Searcher(name)

Represents a global search with label name.

setup_search(name, scf_file, structure_file=scf_file; kwargs...)

Creates and saves a new Searcher with name taking the pw input parameters from the template scf_file and the structure from structure_file, which can be either a pw input or a .cif file. This is the backend method used for the romeo searcher create from the command line.

Structure Kwargs

• primitive=false: set this to true to first try to find the primitive unit cell
• supercell=[1,1,1]: number specifying the number of unit cells along a, b and c direction
• pseudoset=nothing: label (string) of pseudoset to use, if this is nothing it will trigger interactive setup
• U_values=nothing: Dict{Symbol, Float64} of U values to use for the constrained manifolds if it is nothing it will trigger interactive setup

Control Kwargs

• verbosity=0: the logging verbosity, higher = more. See Data for more info
• sleep_time=30: time in seconds between update polls of the Searcher
• server=nothing: label of Server on which to run everything
• exec=nothing: label of the pw.x executable on server to use for the search
• environment=nothing: label of the Environment to use for running all calculations
• priority=nothing: number signifying the priority of the Searcher

Search Kwargs

• nrand=10: how many random trials should be performed in a random search generation
• unique_thr=0.1: threshold that determines the uniqueness of electronic states (uses sssp_distance)
• mindist_ratio=0.25: minimum distance a trial should have to previous trials and unique states, defined as the ratio of the mean distance between current unique states
• stopping_unique_ratio=0.2: the ratio of new found unique states to trials in a generation below which the searching will stop
• stopping_n_generations=3: the search will stop if for this amount of successive generations the unique to trial ratio is lower than the stopping_unique_ratio
• Hubbard_maxstep=100: maximum constraining steps
• Hubbard_mixing_beta=0.4: mixing used to update the constraints during scf iterations
• Hubbard_strength=1.0: strength of the constraining potential
• Hubbard_conv_thr=0.1: threshold euclidean distance per atom between trial and current occupation matrices after which the constraints are released
• electron_maxstep=500: see QE documentation

Pre/Post processing Kwargs:

• relax_unique=false: whether a structural relaxation should be ran on each unique state
• relax_base=false: whether a relaxation should be ran so the search happens for the relaxed structure
• relax_force_convergence_threshold=1e-3: forc_conv_thr in QE
• relax_energy_convergence_threshold=1e-4: energy_conv_thr in QE
• relax_ion_dynamics="bfgs": ion_dynamics in QE
• relax_cell_dynamics="bfgs": cell_dynamics in QE
• relax_no_symmetry=false: whether symmetry should be released during relaxation
• relax_no_variable_cell=false: whether the cell should be relaxed (false) or just the atomic positions (true)
• hp_base=false: whether to calculate U parameters self-consistently before starting the search
• hp_unique=false: whether to recalculate U self-consistently for each unique state
• hp_nq=(2,2,2): nq1, nq2, nq3 in hp.x input
• hp_conv_thr_chi=1e-4: conv_thr_chi in hp.x input
• hp_find_atpert=2: find_atpert in hp.x input
• hp_U_conv_thr=0.1: threshold for self-consistency of U

load(s::Searcher; version)

Loads the Searcher data from disk, from the ledger.jld2 that is associated with the latest Database version if version is unspecified. See Data for more info.

Example

s = load(Searcher("my_searcher_name"))

save(s::Searcher)

Saves s to the standard location as specified in Data.

sssp_distance(bands1, bands2, fermi)

Calculates

\[\sqrt{\frac{\sum_{mk} f_{mk} (\varepsilon^1_{mk} - \varepsilon^2_{mk} + \Delta)^2}{\sum_{mk}f_{mk}}}\]

for bands1 and bands2 flattened bandstructures. fermi is used to crudely determine $f_{mk}$ and $\Delta$ is optimized to minimize the distance.