CHIANTI Technical Report No. 16: CHIANTI lookup tables for fast calculations

This document describes how level population lookup tables are created and used for the CHIANTI database. The tables are used to speed up calculations of emissivities and synthetic spectra. CHIANTI consists of a critically evaluated set of up-to-date atomic data, together with user-friendly programs written in Interactive Data Language (IDL) and Python to calculate the spectra from astrophysical plasmas.This document was previously distributed through the CHIANTI webpage (https://chiantidatabase.org)