QIRM calculates the total energy of atoms, bulk solids and solid surfaces with the Variational quantum Monte Carlo (VMC) method as the expectation value of the exact many-body Hamiltonian with full Coulomb interactions. To obtain the ground state of a given system the optimal variational parameters in the corresponding many-particle wave function are determined according to Ritz' Variational principle. The high-dimensional integration is performed stochastically by the Metropolis algorithm.
The program has been applied to the atomic and bulk ground state of Li and GaAs, to different models of the (110) surface of GaAs, to long-wavelength optical phonons in GaAs, and to electron-phonon coupling in GaAs.
The program is written in Fortran and was tested on different unix platforms and network topologies. It can be used in sequential mode as well as in a highly scalable parallel version based on MPI. The package is still under construction.