GET /ie.pl

nist.gov:nist-atomic-spectra-database-api

Summary: Get ionization energies and ground states
Operation ID: getIonizationEnergies
Auth: unknown
Description

Retrieves ionization energy data and ground state information for specified atomic spectra. Returns HTML with ionization energies in various units.

Parameters (4)

format (integer, query, optional, default: 0)

Output format (0=HTML, 1=ASCII text)

Constraints: {'enum': [0, 1]}

order (integer, query, optional, default: 0)

Sort order (0=atomic number, 1=isoelectronic sequence)

Constraints: {'enum': [0, 1]}

spectra (string, query, required)

Atomic spectra specification (e.g., 'H I', 'He I-II', 'C I; N II; O III', 'Fe I-XII')

units (integer, query, optional, default: 0)

Energy units (0=cm-1, 1=eV, 2=Rydberg)

Constraints: {'enum': [0, 1, 2]}

Examples (2)

TitleTypeURLAction
Get ionization energies and ground states openapi-spec https://physics.nist.gov/cgi-bin/ASD/ie.pl?spectra=H I
Get ionization energies and ground states probe-gate https://physics.nist.gov/cgi-bin/ASD/ie.pl?spectra=H+I&units=0&format=0&order=0

Probe History

Latency

Status Codes

TimeStatusLatencySize
2026-03-23 10:42:49.187259 200 654ms
2026-03-23 10:13:47.796335 200 661ms

Response Changes

WhenOldNew
2026-03-23 10:42:49.187259 13eb68e0d7d5 5a345b34eeea