Crystal structure, Hirshfeld topology analysis, enrichment ratio, energy framework and DFT computational studies of piezoelectric l-histidinium tetrafluoroborate single crystal

The nonlinear L-histidinium tetrafluoroborate (LHFB) single crystals have been grown by the slow evaporation method. The single-crystal XRD confirms the monoclinic lattice system with the P2₁ space group and explains molecular electron charge density distribution for grown crystals. The diffraction data are refined to a final Refinement factor (R) value of 0.04. The growth rate of LHFB crystal is determined by a morphological study. The 3D Hirshfeld surface gives information about the intermolecular interaction present and the 2D fingerprint plot shows the nature of intermolecular close contact experienced by the molecules in a crystal. Energy frameworks have been computed by the Hirshfeld topology. The value of the enrichment ratio has been deduced to help understand the crystal packing interaction. 3D energy framework is a new way for understanding the topology of all types of interaction of the molecule in the crystal. The lower value of the dielectric loss at higher frequencies has increased the optical quality of the crystal. The piezoelectric property was reported for the first time in LHFB single crystal. The piezoelectric charge coefficient (d₃₃) is found to be 4 pC/N. The promising piezoelectric and dielectric studies of grown crystal make it suitable for various optoelectronics, energy harvesting, piezoelectric transducers and patch antennae for wireless communication applications. Mechanical properties reveal that the LHFB crystals belong to the softer nature. The voids present in the grown crystal were estimated at different isosurface values, which give information about the mechanical strength and porosity of the compound. The computing of geometric parameters, optimization energies, frontier molecular orbital energies and molecular surface electrostatic potential were performed using the Gaussian 09 program package in the DFT/B3LYP/6-311++G(d,p) basis set.