qmpy_rester

A python wrapper for OQMD API (PyPI). This code is written in python 3.

Installation

pip install qmpy_rester

Usage

1. Get data through omqd-api

1.1 Example

import qmpy_rester as qr

## Return list of data
with qr.QMPYRester() as q:
    kwargs = {
        ‘element_set’: ‘(Fe-Mn),O’,      # composition include (Fe OR Mn) AND O
        ‘stability’: ‘<-0.1’,            # hull distance smaller than -0.1 eV
        ‘natom’: ‘<10’,                  # number of atoms less than 10
        }
    list_of_data = q.get_oqmd_phases(**kwargs)

## Return data of a single oqmd phase
with qr.QMPYRester() as q:
    phase = q.get_oqmd_phase_by_id(fe_id=4061139, fields='!sites') # Default: fields=None

1.2 Allowed attributes

• composition: compostion of the materials or phase space, e.g. Al2O3, Fe-O
• element_set: the set of elements that the compound must have, '-' for OR, ',' for AND, e.g. (Fe-Mn),O
• icsd: whether the structure exists in ICSD, e.g. False, True, F, T
• prototype: structure prototype of that compound, e.g. Cu, CsCl
• generic: chemical formula abstract, e.g. AB, AB2
• spacegroup: the space group of the structure, e.g. Fm-3m
• natoms: number of atoms in the supercell, e.g. 2, >5
• volume: volume of the supercell, e.g. >10
• ntypes: number of elements types in the compound, e.g. 2, <3
• stability: hull distance of the compound, e.g. 0, <-0.1,
• delta_e: formation energy of that compound, e.g. <-0.5,
• band_gap: band gap of the materials, e.g. 0, >2
• fields: return subset of fields, e.g. 'name,id,delta_e', '!sites'
• filter: customized filters, e.g. 'element_set=O AND ( stability<-0.1 OR delta_e<-0.5 )'
• limit: number of data return at once
• offset: the offset of data return

2. Get data through optimade api format

2.1 Example

import qmpy_rester as qr

## Return list of data
with qr.QMPYRester() as q:
    kwargs = {
        ‘elements’: ‘Fe,Mn’,                    # include element Fe and Mn
        ‘nelements’: ‘<5’,                      # less than 4 element species in the compound
        ‘_oqmd_stability’: ‘<0’,                # stability calculted by oqmd is less than 0
        }
    list_of_data = q.get_optimade_structures(**kwargs)

## Return data of a single structure
with qr.QMPYRester() as q:
    structure = q.get_optimade_structure_by_id(id=4061139, fields='!_oqmd_sites') # Default: fields=None

1.2 Allowed attributes

• elements: the set of elements that the compound must have, e.g. Si,O
• nelements: number of elements types in the compound, e.g. 2, <3
• chemical_formula: compostion of the materials, e.g. Al2O3
• formula_prototype: chemical formula abstract, e.g. AB, AB2
• _oqmd_natoms: number of atoms in the supercell, e.g. 2, >5
• _oqmd_volume: volume of the supercell, e.g. >10
• _oqmd_spacegroup: the space group of the structure, e.g. Fm-3m
• _oqmd_prototype: structure prototype of that compound, e.g. Cu, CsCl
• _oqmd_stability: hull distance of the compound, e.g. 0, <-0.1,
• _oqmd_delta_e: formation energy of that compound, e.g. <-0.5,
• _oqmd_band_gap: band gap of the materials, e.g. 0, >2
• fields: return subset of fields, e.g. 'elements,chemical_formula', '!_oqmd_sites'
• filter: customized filters, e.g. 'elements=O AND ( _oqmd_stability<-0.1 OR _oqmd_delta_e<-0.5 )'
• limit: number of data return at once
• offset: the offset of data return