<p>A single crystal of Triethylenediaminium Hydronium Trinitrate (TEDHT) was grown by using slow evaporation solution technique (SEST). Triethylenediaminium is also known as piperazine. The structural analysis such as crystal system and unit cell parameter of the grown TEDHT crystal was examined by single-crystal XRD analysis, and it exposed that the TEDHT crystal has a trigonal crystal system and space group P 3 1 c. Using powder XRD analysis, miller index and (h k l) planes were identified. The TEDHT crystal has a sharp cutoff wavelength around 320&#xa0;nm and is transparent in UV region. The FTIR analysis was investigated on the TEDHT crystal to find out the TEDHT functional groups. The thermogravimetric and differential thermal analyses illustrate that the TEDHT crystal is thermally stable upto 96&#xa0;°C. The positive photoconductivity nature of the TEDHT crystal was measured by photoconductivity analysis. The dielectric constant (ε′) and dielectric loss (tan δ) as a function of frequency were measured for the grown crystal. Chemical etching study was carried out, and the etch pit density (EPD) was calculated. The mechanical stability of the grown TEDHT crystal was studied using Vickers microhardness measurement. The NLO susceptibility (χ⁽³⁾) was calculated by the Z-scan method using the source of the He–Ne laser, of which wavelength is 632.8&#xa0;nm.</p>