Enter an atomic species: Cu Enter a cubic lattice type: fcc Enter a model name: MEAM_LAMMPS_KimSeolJi_2017_PtCu__MO_070797404269_001 Enter a lattice constant (m): 3.917371600866318e-10 WARNING, 2 imaginary frequencies at q = ( 0.00, 0.00, 0.00) ; (omega_q = 8.855e-09*i) WARNING, 2 imaginary frequencies at q = ( 0.00, 0.00, 0.00) ; (omega_q = 8.855e-09*i)