research papers J. Appl. Cryst. (2017). 50, 763–768 https://doi.org/10.1107/S1600576717004241 763 Received 10 October 2016 Accepted 16 March 2017 Edited by J. M. Garcı ´a-Ruiz, Instituto Andaluz de Ciencias de la Tierra, Granada, Spain Keywords: seed rotation technique; X-ray diffraction; photoluminescence; shock damage threshold; photoacoustic spectroscopy. Growth of a bulk-size single crystal of sulphamic acid by an in-house developed seed rotation solution growth technique and its characterization Sonia, a,b N. Vijayan, a * Medha Bhushan, c Kanika Thukral, a,b Rishabh Raj, d K. K. Maurya, b D. Haranath b and S. A. Martin Britto Dhas e a Academy of Scientific and Innovative Research, CSIR – National Physical Laboratory, New Delhi 110012, India, b CSIR – National Physical Laboratory, Dr K. S. Krishnan Road, New Delhi 110 012, India, c AIAS, Amity University, Uttar Pradesh, Noida 201303, India, d SENSE, VIT University, Chennai 600127, India, and e Department of Physics, Sacred Heart College, Tirupattur, Vellore 635601, India. *Correspondence e-mail: vjnphy@gmail.com A bulk sulphamic acid single crystal has been grown by a modified seed rotation technique. The lattice dimensions of the grown single crystal were confirmed using powder X-ray diffraction, and it was found that it crystallized in an orthorhombic structure with space group Pbca. The strain in the lattice was calculated by the Williamson–Hall equation. The crystalline perfection was examined by high-resolution X-ray diffraction and found to be extremely good (the single peak of the rocking curve having an FWHM of 8.0 00 ). The luminescence behaviour was recorded in the wavelength region between 400 and 630 nm using an Xe flash lamp which acts as an excitation source. The shock damage threshold was measured for the grown crystal in order to determine the mechanical capability of the title compound. The thermal parameter of sulphamic acid was calculated by photoacoustic spectroscopy. 1. Introduction Numerous research efforts have been undertaken in the development of nonlinear optical (NLO) compounds owing to their applications in electro-optic switches, harmonic genera- tors, optical communications, optical computing, data storage, dynamic holography etc. Many organic compounds have a conjugated electron system, containing an electron donor group on one side and an electron acceptor group on the other, which leads to a high NLO efficiency (Nagaraja et al., 1998). But the disadvantage is that these molecules are linked by weak van der Walls and hydrogen bonds, which make the material soft (Chemla & Zyss, 1987). On the other hand, inorganic compounds with NLO properties are highly stable and hard. Sulphamic acid (SA) is an inorganic material with orthorhombic structure belonging to the Pbca space group (Lenin et al., 2007). It is highly stable at room temperature – we have kept it for several years without noting any change in its properties. It is a strong inorganic acid, which is moderately soluble in water (Senthil Pandian et al., 2010). Sulphamic acid forms zwitterions when dissolved in water and possesses outstanding catalytic features which make it different from other acidic catalysts (Jat et al., 2013). Because of these advantages, the Japanese Industrial Standards Committee has considered this reagent as a standard substance for titrimetric analysis (Yoshimori & Tanaka, 1973). So far, various authors have reported growing sulphamic acid by the conventional slow evaporation solution growth method, and it has been ISSN 1600-5767 # 2017 International Union of Crystallography