Basis Set Specs

Description

A cluster expansion basis set is specified by two components, one specifying basis function type and order, and one specifying cluster orbits.

Project files

This format is used for the bspecs.json file.

JSON Attributes List

ClexBasisSpecs attributes:

Name Description Format
basis_function_specs Basis function specifications Basis Function Specs
cluster_specs Cluster orbit specifications Cluster Specs

JSON Attributes Description

Examples

Example 1) Periodic cluster expansion

{
  "basis_function_specs" : {
    "global_max_poly_order": 3,
    "dof_specs": {
      "occ": {
        "site_basis_functions" : "occupation"
      }
    }
  },
  "cluster_specs": {
    "method": "periodic_max_length",
    "params": {
      "orbit_branch_specs": {
        "2" : {"max_length" : 6.},
	      "3" : {"max_length" : 3.}
      }
    }
  }
}

Example 2) Local cluster expansion

{
  "basis_function_specs" : {
    "dof_specs": {
      "occ": {
        "site_basis_functions" : "occupation"
      }
    }
  },
  "cluster_specs": {
    "method": "local_max_length",
    "params": {
      "phenomenal": {
        "coordinate_mode": "Integral",
        "sites": [
          [ 1, 0, 0, 0 ],
          [ 0, 1, 0, 0 ]
        ]
      },
      "generating_group": [ 0, 7, 11, 17, 18, 19, 26, 27, 28, 33, 37, 47 ],
      "orbit_branch_specs": {
        "1" : {"cutoff_radius": 6.},
        "2" : {"cutoff_radius": 3., "max_length" : 3.}
      }
    }
  }
}