Optimal system-specific coherent states for excited state calculations of quantum systems

Highlights: • Optimal discretized system-specific coherent states are developed. • Fluctuations in energy are minimized for excited state calculations. • Accurate energy eigenvalues and eigenfunctions are obtained. Optimal discretized system-specific coherent states are developed as a set of basis functions to calculate the excited state energies and wave functions of a quantum system. The ground state of the system is employed as a fiducial function to generate system-specific coherent states. Discretizing the continuous label in the system-specific coherent state yields a set of basis functions distributed in phase space. Minimizing the deviation of the trial wave function from being a true eigenstate of the Hamiltonian, we obtain the optimal distribution of discretized system-specific coherent states in phase space for excited state calculations.