1：Experimental Design and Method Selection:

The study employed slow evaporation solution growth technique for crystal growth, utilizing single crystal X-ray diffraction, FTIR spectroscopy, UV–Vis spectroscopy, TG/DTA analysis, Kurtz Perry powder SHG technique, Vicker’s microhardness test, and dielectric studies for characterization.

2：Sample Selection and Data Sources:

Stoichiometric amounts of l-arginine and sodium nitrate in double distilled water were used for crystal growth.

3：List of Experimental Equipment and Materials:

BRUKER KAPPA APEX II CCD diffractometer, PERKIN ELMER spectrometer, PERKIN ELMER LAMADA 35 spectrophotometer, NANO TECHNOLOGY-MODEL TG/DTA 6200 thermal analyser, Nd:YAG laser, SHIMADZU HMV microhardness tester, HIOKI 3532 LCR Hitester.

4：Experimental Procedures and Operational Workflow:

The mixture was stirred continuously for 12 h, filtered, and left for slow evaporation. Characterization techniques were applied to the grown crystal.

5：Data Analysis Methods:

Optical band gap energy was calculated using Tauc’s plot, SHG efficiency was compared with KDP, and dielectric properties were analyzed as a function of frequency.