  Method(s) that can reliably predict phase evolution across thermodynamic
parameter space, especially in complex systems are of critical significance in
academia as well as in the manufacturing industry. In the present work, phase
stability in equimolar AlCuFeMn multi-principal-component alloy (MPCA) was
predicted using complementary first-principles density functional theory (DFT)
calculations, and ab-initio molecular dynamics (AIMD) simulations. Temperature
evolution of completely disordered, partially ordered, and completely ordered
phases was examined based on Gibbs free energy. Configurational, electronic,
vibrational, and lattice mismatch entropies were considered to compute the
Gibbs free energy of the competing phases. Additionally, elemental segregation
was studied using ab-initio molecular dynamics (AIMD). The predicted results at
300K align well with room-temperature experimental observations using x-ray
diffraction, scanning and transmission electron microscopy on a sample prepared
using commercially available pure elements. The adopted method could help in
predicting plausible phases in other MPCA systems with complex phase stability.
