New carbon-filled G phase, 30-atom primitive cell relaxed in PBE (ABACUS, TZDP, k-spacing 0.2, forces < 0.04 eV/Å). 18.2 meV/atom below Zr₆Fe₁₆Si₇ + ZrC + Zr₂Fe₂Si₂C + Fe₃Si; weakly magnetic; no imaginary phonon modes. Relaxed from the Orb geometry in this file's family. Sun-tetragonal campaign, loop 5.