httk property definitionsProperty definitions using the OPTIMADE property definition format, hosted by httk
This page documents an OPTIMADE Property Definition. See https://schemas.optimade.org/ for more information.
ID: https://schemas.httk.org/defs/v0.1/properties/validation/nve_energy_drift
Definition name: nve_energy_drift
Property name: NVE energy drift
Description: Linear drift of the conserved total energy (kinetic plus potential) per atom along a selected interval of a trajectory in the NVE ensemble.
Type: dictionary
Implementation requirements:
- Support: OPTIONAL support in implementations, i.e., MAY be null.
Total energies are divided by the number of atoms before the fit; a straight line is fitted by least squares against time over all selected samples.
Requirements/Conventions:
slope (eV per atom per ps, unit eV*ps^-1) is the fitted slope.intercept (eV per atom) is the fitted energy at start.residual_rms (eV per atom) is the root mean square of the fit residuals over all samples, of the per-atom energies.endpoint_change (eV per atom) is the observed energy at the last sample minus that at the first.start and stop (ps) are the first and last sample times.samples is the number of samples (at least three).A null value means the quantity is not available or not recorded.
Examples:
JSON definition:
{
"$id": "https://schemas.httk.org/defs/v0.1/properties/validation/nve_energy_drift",
"$schema": "https://schemas.optimade.org/meta/v1.3/optimade/property_definition.json",
"title": "NVE energy drift",
"x-optimade-type": "dictionary",
"x-optimade-definition": {
"kind": "property",
"version": "0.1.0",
"format": "1.3",
"name": "nve_energy_drift",
"label": "nve_energy_drift_validation_httk"
},
"x-optimade-unit": "inapplicable",
"x-optimade-unit-definitions": [
{
"$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/electronvolt",
"title": "electron volt",
"symbol": "eV",
"display-symbol": "eV",
"description": "A unit of energy that representing the kinetic energy acquired by an electron as it accelerates through a 1 volt potential difference in a vacuum using the current, or one of the historical, definitions given in the editions of the International System of Units (SI).\n\nThe electronvolt unit appears in the International System of Units (SI), 1st ed. (1970) defined as \"1 electronvolt is the energy acquired by an electron after traversing a potential difference of 1 V in a vacuum; 1 eV = 1.60219\u00d710\u207b\u00b9\u2079 J approximately.\"\nThis definition makes the unit equal to 1 volt times the value of the elementary charge.\nIn the 2019 redefinition of the SI units the elementary charge is exactly 1.602176634\u00b710\u207b\u00b9\u2079 C, making the electron volt exactly equal to 1.602176634\u00b710\u207b\u00b9\u2079 J.\nThe International System of Units (SI), 9th ed. (2019) accordingly notes the exact relationship with the SI 2019 derived unit joule as \"1 eV = 1.602176634\u00b710\u207b\u00b9\u2079 J\" but retains the definition from 1970 in a footnote.\n\nThe unit is categorized in the International System of Units (SI), 9th ed. (2019) as \"Non-SI units accepted for use with the SI units\".\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
"compatibility": [
"https://schemas.optimade.org/defs/v1.2/units/si/1970/accepted/electronvolt",
"https://schemas.optimade.org/defs/v1.2/units/si/1983/accepted/electronvolt",
"https://schemas.optimade.org/defs/v1.2/units/si/2019/accepted/electronvolt"
],
"resources": [
{
"relation": "Definition in the International System of Units (SI), 9th Edition",
"resource-id": "https://www.bipm.org/en/publications/si-brochure"
},
{
"relation": "Wikipedia article describing the unit",
"resource-id": "https://en.wikipedia.org/wiki/Electronvolt"
}
],
"approximate-relations": [
{
"base-units": [
{
"symbol": "V",
"id": "https://schemas.optimade.org/defs/v1.2/units/si/general/volt"
},
{
"symbol": "e",
"id": "https://schemas.optimade.org/defs/v1.2/constants/codata/2018/electromagnetic/elementarycharge"
}
],
"base-units-expression": "e*V"
}
],
"x-optimade-definition": {
"label": "electronvolt_si_general",
"kind": "unit",
"format": "1.2",
"version": "1.2.0",
"name": "electronvolt"
}
},
{
"$id": "https://schemas.optimade.org/defs/v1.2/prefixes/si/pico",
"title": "pico",
"symbol": "p",
"display-symbol": "p",
"description": "The pico SI prefix defined as a dimensionless multiple of 10\u207b\u00b9\u00b2, adopted into SI at its creation at the 11th CGPM Meeting in 1960, resolution 12.",
"resources": [
{
"relation": "Definition in the 11th CGPM Meeting in 1960, resolution 12",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-12"
},
{
"relation": "Wikipedia article describing the SI prefixes",
"resource-id": "https://en.wikipedia.org/wiki/Metric_prefix"
}
],
"defining-relation": {
"base-units": [],
"base-units-expression": "",
"scale": {
"exponent": -12
}
},
"x-optimade-definition": {
"label": "pico_prefix_si",
"kind": "prefix",
"format": "1.2",
"version": "1.2.0",
"name": "pico"
}
},
{
"$id": "https://schemas.optimade.org/defs/v1.2/units/si/general/second",
"title": "second",
"symbol": "s",
"display-symbol": "s",
"description": "A unit of time using the current, or one of the historical, definitions of the SI units.\n\nThe current definition in its most recent phrasing at the 26th CGPM Meeting in 2018, resolution 1 is: \"The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency, \\(\\Delta \\nu_\\textrm{Cs}\\), the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9192631770 when expressed in the unit Hz, which is equal to s\u207b\u00b9.\"\n\nThis is a rephrasing of a definition at the 13th CGPM Meeting (1967), resolution 1: \"The second is the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom.\"\n\nThe earlier definition at the 11th CGPM Meeting in 1960, resolution 9 was: \"The second is the fraction 1/31556925.9747 of the tropical year for 1900 January 0 at 12 hours ephemeris time.\"\n\nThis is a generalized definition taken to reference the current, or one of the historical, SI unit definitions.\nThis definition is intended for situations when it is not possible to be more precise, e.g., in contexts where data have been collected that uses different historical SI definitions.",
"compatibility": [
"https://schemas.optimade.org/defs/v1.2/units/si/1960/base/second",
"https://schemas.optimade.org/defs/v1.2/units/si/1967/base/second"
],
"resources": [
{
"relation": "Definition in the 13th CGPM Meeting (1967), resolution 1",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/13-1967/resolution-1"
},
{
"relation": "Rephrased definition in the 26th CGPM Meeting (2018), resolution 1",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/26-2018/resolution-1"
},
{
"relation": "Definition at the 11th CGPM meeting (1960), resolution 6.",
"resource-id": "https://www.bipm.org/en/committees/cg/cgpm/11-1960/resolution-6"
},
{
"relation": "Wikipedia article describing the unit",
"resource-id": "https://en.wikipedia.org/wiki/Second"
}
],
"x-optimade-definition": {
"label": "second_si_general",
"kind": "unit",
"format": "1.2",
"version": "1.2.0",
"name": "second"
}
}
],
"x-optimade-requirements": {
"support": "may",
"sortable": false,
"query-support": "none"
},
"type": [
"object",
"null"
],
"required": [
"slope",
"intercept",
"residual_rms",
"endpoint_change",
"start",
"stop",
"samples"
],
"description": "Linear drift of the conserved total energy (kinetic plus potential) per atom along a selected interval of a trajectory in the NVE ensemble.\n\nTotal energies are divided by the number of atoms before the fit; a straight line is fitted by least squares against time over all selected samples.\n\n**Requirements/Conventions**:\n\n- `slope` (eV per atom per ps, unit `eV*ps^-1`) is the fitted slope.\n- `intercept` (eV per atom) is the fitted energy at `start`.\n- `residual_rms` (eV per atom) is the root mean square of the fit residuals over all samples, of the per-atom energies.\n- `endpoint_change` (eV per atom) is the observed energy at the last sample minus that at the first.\n- `start` and `stop` (ps) are the first and last sample times.\n- `samples` is the number of samples (at least three).\n\nA null value means the quantity is not available or not recorded.",
"properties": {
"slope": {
"x-optimade-type": "float",
"x-optimade-unit": "eV*ps^-1",
"type": [
"number"
]
},
"intercept": {
"x-optimade-type": "float",
"x-optimade-unit": "eV",
"type": [
"number"
]
},
"residual_rms": {
"x-optimade-type": "float",
"x-optimade-unit": "eV",
"type": [
"number"
]
},
"endpoint_change": {
"x-optimade-type": "float",
"x-optimade-unit": "eV",
"type": [
"number"
]
},
"start": {
"x-optimade-type": "float",
"x-optimade-unit": "ps",
"type": [
"number"
]
},
"stop": {
"x-optimade-type": "float",
"x-optimade-unit": "ps",
"type": [
"number"
]
},
"samples": {
"x-optimade-type": "integer",
"x-optimade-unit": "dimensionless",
"type": [
"integer"
]
}
}
}