Multifunctional lanthanum nitrides under high pressure

Lanthanum nitrides are a class of multifunctional materials possessing distinctive properties that render them promising candidates for a wide variety of applications in electronic devices, optoelectronics, and energy conversion and storage. Here, we have several stable lanthanum nitrides under high pressure by using the reverse structure design method in conjunction with first-principles calculations. Our structural searches indicate that the Imm2 phase of LaN are stable at ambient pressure. Interestingly, the Imm2 phase of LaN is a semiconductor with band gap of 1.48 eV, indicating potential for application in optoelectronic device. The \({{P}}\overline{{1}}\) phase of \({\text{LaN}}_{4}\) exhibits semimetallic property with a narrow band gap of 0.09 eV at ambient pressure. The \({{P}}{{4}_{3}} {2}_{1}\)2 phase of \({\text{LaN}}_{5}\) displays promise as a high-energy material is a potential high-energy material, possessing the energy density of 2.21 kJ/g. The present findings enrich the stoichiometries of lanthanum nitrogen compounds and offer valuable insights for the further design and synthesis of multifunctional materials.