Hydrogen-rich compounds under high pressure have been attractive in high temperature superconductors. By using the genetic algorithm (GA) method combined with first-principles calculations, H6Se structures are predicted at high pressure, and the formation enthalpies per atom and phonon spectrum of H6Se are analyzed. Furthermore, the superconductivity properties of H6Se are investigated. Pmma is found to be the most stable phase of H6Se at 50–270 GPa, and the predicted Tc values are 19–39 K. By contrast, C2/m becomes the most stable phase of H6Se above 270 GPa and its Tc values are predicted to be 50–87 K.
