  QMCPACK is an open source quantum Monte Carlo package for ab-initio
electronic structure calculations. It supports calculations of metallic and
insulating solids, molecules, atoms, and some model Hamiltonians. Implemented
real space quantum Monte Carlo algorithms include variational, diffusion, and
reptation Monte Carlo. QMCPACK uses Slater-Jastrow type trial wave functions in
conjunction with a sophisticated optimizer capable of optimizing tens of
thousands of parameters. The orbital space auxiliary field quantum Monte Carlo
method is also implemented, enabling cross validation between different highly
accurate methods. The code is specifically optimized for calculations with
large numbers of electrons on the latest high performance computing
architectures, including multicore central processing unit (CPU) and graphical
processing unit (GPU) systems. We detail the program's capabilities, outline
its structure, and give examples of its use in current research calculations.
The package is available at http://www.qmcpack.org .
