Input Files

Most NeuralXC CLI commands require two types of input files:

• preprocessor file : Contains information regarding the density projection basis, as well

as the projector and symmetrizer type. Instructions on how to run SCF calculations such as the type of driver code as well as the basis sets etc. should also be contained.

• hyperparameters file : Contains the hyperparameters used the machine learning model (anything following symmetrization). Details are provided below.

Preproccesor

Let’s start with an example:

pyscf with analytical gaussian projectors:

{
  "preprocessor":
  {
       "basis": "cc-pVTZ-jkfit",
       "extension": "chkpt",
       "application": "pyscf",
       "projector_type": "pyscf",
       "symmetrizer_type": "trace"

  },
  "n_workers" : 1,
  "engine_kwargs": {"xc": "PBE",
                    "basis" : "cc-pVTZ"}

}

“n_workers” determines over how many processes SCF calculations and subsequent density projections are distributed. Apart from this, there are two groups:

• “preprocessor” contains the necessary information to project the density and symmetrize it.
• “engine_kwargs” determines the behavior of the electronic structure code specified in preprocessor[application].

In our example we use PySCF and project the density analytically onto Gaussian type orbitals with the “pyscf” projector using the “cc-pVTZ-jkfit” basis . For a selection of different projectors, see Projector.

SIESTA with numerical polynomial projectors:

{
    "preprocessor": {
        "C": {
            "n": 4,
            "l": 5,
            "r_o": 2
        },
        "H": {
            "n": 4,
            "l": 5,
            "r_o": 2
        },
        "extension": "RHOXC",
        "applications": "siesta",
        "projector_type": "ortho",
        "symmetrizer_type": "trace"

    },
    "src_path": "workdir",
    "n_workers": 1,
    "engine_kwargs": {"pseudoloc" : ".",
                      "fdf_path" : null,
                      "xc": "PBE",
                      "basis" : "DZP",
                      "fdf_arguments": {"MaxSCFIterations": 50}
}