  We investigate the possibility to calculate the ground-state energy of the
atomic systems on a quantum computer. For this purpose we evaluate the lowest
binding energy of the moscovium atom with the use of the iterative phase
estimation and variational quantum eigensolver. The calculations by the
variational quantum eigensolver are performed with a disentangled unitary
coupled cluster ansatz and with various types of hardware-efficient ansatze.
The optimization is performed with the use of the Adam and Quantum Natural
Gradients procedures. The scalability of the ansatze and optimizers is tested
by increasing the size of the basis set and the number of active electrons. The
number of gates required for the iterative phase estimation and variational
quantum eigensolver is also estimated.
