Using evolutionary algorithm to calculate the ground-state energy of double-electron atoms in a uniform magnetic field (B <= 10(9) G)

It is very difficult to calculate the accurate ground-state energies of the double-electron atom like helium in a uniform magnetic field. By using the modified configuration interaction (MCI) method and the evolutionary algor ithm (EA), we obtained highly accurate results. We discuss the role of magn etic field in the ground state of the double-electron system and the possib ility of variational ground-state energy calculation by using evolutionary algorithm directly. Results show that compared with other algorithms, such as the simplex method, EA is more efficient in calculating atomic energies, and can be used in other fields of physics.