2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/122322We present a variational Monte Carlo (VMC) method that works equally well for the ground and the excited states of a quantum system. The method is based on the minimization of the variance of energy, as opposed to the energy itself in standard methods. As a test, it is applied to the investigation of the universal spectrum at the van der Waals length scale for two identical Bose atoms in a symmetric harmonic trap, with results compared to the basically exact results obtained from a multiscale quantum-defect theory.5 pages, 3 figuresComputational PhysicsAtomic Physicstext