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Structured Representation of Models

The example of a JSON data structure for a model, based upon the Exabyte Data Convention, is shown below together with an associated example.

The corresponding method components are also included in this example, and are explained further in this section of the documentation.

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{
    "$schema": "http://json-schema.org/draft-04/schema#", 
    "required": [
        "type", 
        "subtype", 
        "method"
    ], 
    "properties": {
        "subtype": {
            "type": "string", 
            "description": "general subtype of the model, eg. `lda`"
        }, 
        "type": {
            "type": "string", 
            "description": "general type of the model, eg. `dft`"
        }, 
        "method": {
            "required": [
                "type", 
                "subtype"
            ], 
            "properties": {
                "subtype": {
                    "type": "string", 
                    "description": "general subtype of this method, eg. `ultra-soft`"
                }, 
                "type": {
                    "type": "string", 
                    "description": "general type of this method, eg. `pseudopotential`"
                }, 
                "precision": {
                    "type": "object", 
                    "description": "Object showing the actual possible precision based on a theory and exact method of implementation", 
                    "title": "precision schema"
                }, 
                "data": {
                    "type": "object", 
                    "description": "additional data specific to method, eg. array of pseudopotentials"
                }
            }, 
            "title": "method schema (base)"
        }, 
        "references": {
            "items": {
                "type": "string", 
                "description": "literature reference, webpage etc."
            }, 
            "type": "array"
        }, 
        "accuracy": {
            "items": {
                "required": [
                    "property", 
                    "value"
                ], 
                "type": "object", 
                "properties": {
                    "property": {
                        "type": "string", 
                        "description": "Name of the property that is prediction is being compared against experimental values or an alternate theory or analysis."
                    }, 
                    "reference": {
                        "items": {
                            "type": "string"
                        }, 
                        "type": "array", 
                        "description": "Sources that describe the data used for validation."
                    }, 
                    "value": {
                        "minimum": 0, 
                        "type": "number", 
                        "description": "Typical fidelity score for the property predicted: 0.99 means an error of 1%", 
                        "maximum": 1
                    }
                }
            }, 
            "type": "array", 
            "description": "Object showing ultimate possible accuracy for a theory implementation", 
            "title": "accuracy schema"
        }
    }, 
    "title": "model schema (base)"
}
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{
    "name": "model", 
    "functional": "pbe", 
    "subtype": "gga", 
    "references": [
        "http://journals.aps.org/prb/abstract/10.1103/PhysRevB.54.16533"
    ], 
    "type": "dft", 
    "method": {
        "subtype": "us", 
        "data": {
            "dataset": {
                "files": [
                    {
                        "valenceElectrons": 4, 
                        "name": "pseudopotential file", 
                        "electronicConfiguration": "s2p2", 
                        "generationDate": "05Jan2001", 
                        "textHeading": "PAW_PBE Si 05Jan2001\n   4.00000000000000\nparameters from PSCTR are:\n   VRHFIN =Si: s2p2\n   LEXCH  = PE\n   EATOM  =   103.0669 eV,    7.5752 Ry\n \n   TITEL  = PAW_PBE Si 05Jan2001\n   LULTRA =        F    use ultrasoft PP ?\n   IUNSCR =        1    unscreen: 0-lin 1-nonlin 2-no\n   RPACOR =    1.500    partial core radius\n   POMASS =   28.085; ZVAL   =    4.000    mass and valenz\n   RCORE  =    1.900    outmost cutoff radius\n   RWIGS  =    2.480; RWIGS  =    1.312    wigner-seitz radius (au A)\n   ENMAX  =  245.345; ENMIN  =  184.009 eV\n   ICORE  =        2    local potential\n   LCOR   =        T    correct aug charges\n   LPAW   =        T    paw PP\n   EAUG   =  322.069\n   DEXC   =    0.000\n   RMAX   =    1.950    core radius for proj-oper\n   RAUG   =    1.300    factor for augmentation sphere\n   RDEP   =    1.993    radius for radial grids\n   RDEPT  =    1.837    core radius for aug-charge\n \n   Atomic configuration\n    6 entries     n  l   j            E        occ.\n     1  0  0.50     -1785.8828   2.0000\n     2  0  0.50      -139.4969   2.0000\n     2  1  1.50       -95.5546   6.0000\n     3  0  0.50       -10.8127   2.0000\n     3  1  0.50        -4.0811   2.0000\n     3  2  1.50        -4.0817   0.0000\n   Description\n     l       E           TYP  RCUT    TYP  RCUT\n     0    -10.8127223     23  1.900\n     0     -7.6451159     23  1.900\n     1     -4.0811372     23  1.900\n     1      2.4879257     23  1.900\n     2     -4.0817478      7  1.900\n   Error from kinetic energy argument (eV)\n", 
                        "title": "Si paw pbe vasp 5.2", 
                        "apps": [
                            "vasp"
                        ], 
                        "element": "Si", 
                        "source": "vasp", 
                        "radii": {
                            "units": "angstrom", 
                            "cutoff": 1.9, 
                            "wignerSeitz": 1.312, 
                            "name": "radii", 
                            "partialCore": 1.5
                        }, 
                        "mass": 28.085, 
                        "energyCutoff": {
                            "units": "eV", 
                            "max": 245.345, 
                            "name": "energy cutoff", 
                            "min": 184.009
                        }, 
                        "path": "/export/share/pseudo/ag/gga/pbe/gbrv/1.4/us/ag_pbe_gbrv_1.4.upf", 
                        "type": "paw", 
                        "exchangeCorrelation": {
                            "approximation": "gga", 
                            "functional": "pbe"
                        }
                    }
                ], 
                "elements": [
                    "Si", 
                    "Ge", 
                    "As"
                ], 
                "name": "my set", 
                "format": "upf", 
                "apps": [
                    "espresso"
                ], 
                "source": "gbrv", 
                "version": "1.5", 
                "type": "us", 
                "exchangeCorrelation": {
                    "approximation": "gga", 
                    "functional": "pbe"
                }
            }
        }, 
        "precision": {
            "kgrid": {
                "shifts": [
                    0, 
                    0, 
                    0
                ], 
                "dimensions": [
                    2, 
                    2, 
                    2
                ]
            }, 
            "ecutwfc": 200, 
            "ecutrho": 40
        }, 
        "type": "pseudopotential"
    }, 
    "accuracy": [
        {
            "property": "band gap", 
            "value": 0.9
        }
    ]
}