Enter an atomic species: Kr Enter a cubic lattice type: fcc Enter a model name: LJ_Shifted_Bernardes_1958MedCutoff_Kr__MO_984281096460_003 Enter a lattice constant (m): 5.634428912401205e-10 Writing phonon.eq.pckl Writing phonon.0x-.pckl Writing phonon.0x+.pckl Writing phonon.0y-.pckl Writing phonon.0y+.pckl Writing phonon.0z-.pckl Writing phonon.0z+.pckl WARNING, 2 imaginary frequencies at q = ( 0.00, 0.00, 0.00) ; (omega_q = 2.386e-09*i) WARNING, 2 imaginary frequencies at q = ( 0.00, 0.00, 0.00) ; (omega_q = 2.386e-09*i)