  The work considers a model of charged "semi-hard-core" bosons on a square
lattice with a possible filling number at each node, ranging from 0 to 2.
Temperature phase diagrams of the model are obtained using numerical Monte
Carlo quantum simulation methods, and the influence of local charge
correlations is examined. Comparison with results from mean-field methods shows
that local charge correlations contribute to an increased role of quantum
fluctuations in the formation of phase states.
