  The Discrete Space Quantum Systems Solver (DSQSS) is a program package for
solving quantum many-body problems defined on lattices. The DSQSS is based on
the quantum Monte Carlo method in Feynman's path integral representation and
covers a broad range of problems using flexible input files that define
arbitrary unit cells in arbitrary dimensions and arbitrary matrix elements
representing the interactions among an arbitrary number of degrees of freedom.
Finite temperature calculations of quantum spin and the Bose- Hubbard models
can be performed by specifying parameters such as the number of dimensions, the
lattice size, coupling constants, and temperature. The present paper details
the use of DSQSS and presents a number of applications thereof.
