Fig. 1 a Initial atom model, b corresponding partial pair correlation functions gij(r) for the BCC solid solution of HfNbTaTiZr HEA. As the atoms distribute randomly in the BCC lattice, the gij(r) curves of all the element pairs overlap with each other in Fig. 1b

Fig. 2 a Atomic potential energy, atom fractions, b atom structures during relaxing at 800 K. In order to clearly show the HCP and ‘unknown’ type atoms, BCC type atoms were set invisible in the subfigures (2-5) in Fig. 2b

Fig. 3 a Element distribution, b corresponding partial pair correlation functions gij(r), c structure distribution, d atom fractions in HCP and BCC phases at the final moment 2050 ps

Fig. 4 a Element and structure distribution, b corresponding pair correlation functions gij(r), c Warren-Cowley parameters at 100 ps

Fig. 5 Atom types and element distributions at a 50 ps, b 90 ps, c 107 ps, d 140 ps during relaxing at 800 K

Fig. 6 Atom types from 107 to 109 ps during relaxing at 800 K

Fig. 7 Fractions of bond indexes for all ‘unknown’ type atoms at 90 ps

Fig. 8 Distribution functions of the bond length for different type atoms at a 50 ps, b 90 ps, c 107 ps, d 2050 ps during relaxing at 800 K

Fig. 9 a Number of HCP and ‘unknown’ type atoms during cooling the atom structure obtained at 90 ps at 800 K (Fig. 5b). Atom types at b 600 K, c 300 K, d 10 K. e Potential energy of the atoms during MD/MC relaxing at 10 K. f Element distribution and atom type after MD/MC relaxing for 50 ps at 10 K

Fig. 10 Distribution functions of the bond length at a 800 K, b 600 K, c 300 K, d 10 K. In the figure, ‘all’ means all atoms while cooling the atoms obtained at 90 ps at 800 K and ‘HCP’ means HCP type atoms while cooling the atoms obtained at 2050 ps at 800 K