  The photoionization model of narrow-line regions (NLRs) in active galactic
nuclei (AGNs) has been investigated for decades. Many published models are
restricted to simple linear scaling abundance relations, dust-free assumption,
uniform AGN radiation field, and using one specific photoionization code, which
restricts them from providing a satisfactory prediction on a broad range of AGN
observations. Through a comprehensive investigation, here we present how the
choice of abundance scaling relations, dust inclusion, AGN radiation fields,
and different photoionization codes CLOUDY and MAPPINGS affect the predictions
on the strength of strong UV, optical, and infrared emission lines. We find the
dust-depleted radiation pressure-dominated AGN model built with the latest
non-linear abundance sets and photoionization code MAPPINGS V are consistent
with AGN observations across a broad range of wavelengths. We also assess new
potential HII-AGN separation diagrams in the optical and UV wavelengths.
