Is "L-valine ferric chloride" a new nonlinear optical material?

TL;DR

This paper critically examines the claimed nonlinear optical properties of 'L-valine ferric chloride' and argues that it is not a new material but a questionable crystal.

Contribution

It challenges prior claims by analyzing the crystal's authenticity and questioning its classification as a nonlinear optical material.

Findings

The crystal is likely not a new nonlinear optical material.

The reported crystal may be a dubious or misidentified compound.

Previous claims of its nonlinear optical properties are unsubstantiated.

Abstract

We argue that "L-valine ferric chloride" crystal reported by Geetha et al [Curr. Appl. Phys. 15 (2015) 201-207] is not a new nonlinear optical material but instead a dubious crystal.