{
"title": "quantum espresso arguments schema",
"schemaId": "software-directory-modeling-espresso-arguments",
"additionalProperties": false,
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"properties": {
"ntg": {
"type": "integer",
"description": "In order to allow good parallelization of the 3D FFT when the number of processors exceeds the number of FFT planes, FFTs on Kohn-Sham states are redistributed to `task` groups so that each group can process several wavefunctions at the same time."
},
"ndiag": {
"type": "integer",
"description": "A further level of parallelization, independent on PW or k-point parallelization, is the parallelization of subspace diagonalization / iterative orthonormalization. Both operations required the diagonalization of arrays whose dimension is the number of Kohn-Sham states (or a small multiple of it). All such arrays are distributed block-like across the `linear-algebra group`, a subgroup of the pool of processors, organized in a square 2D grid. As a consequence the number of processors in the linear-algebra group is given by n2, where n is an integer; n2 must be smaller than the number of processors in the PW group. The diagonalization is then performed in parallel using standard linear algebra operations."
},
"nimage": {
"type": "integer",
"description": "Processors can be divided into different `images`, each corresponding to a different self-consistent or linear-response calculation, loosely coupled to others."
},
"npools": {
"type": "integer",
"description": "Each image can be subpartitioned into `pools`, each taking care of a group of k-points."
},
"nband": {
"type": "integer",
"description": "Each pool is subpartitioned into `band groups`, each taking care of a group of Kohn-Sham orbitals (also called bands, or wavefunctions)."
}
}
}