The gcmc program is used to perform a molecular simulation in the grand canonical ensemble. The program is capable of simulating molecular models composed of Lennard-Jones or Buckingham exponential-6 sites to describe the non-polar forces and point charges to represent the polar forces. Configurational-bias techniques are used to insert molecules. The program is also capable of using early rejection and expanded ensemble techniques to aid in inserting the molecules. Additionally, reservoir techniques are available to create molecules with complex architecture and/or stiff intramolecular potentials. The program is written with the assumption that histogram reweighting techniques will be used to calculate the thermophysical properties. Therefore, the main output of the program is a histogram of the frequency of observing the system with a given particle number and energy. Finally, Hamiltonian scaling techniques are incorporated into the program. This allows multiple potential models to be simulated during the same run.
Information is provided on how to obtain and compile the source code. Documentation about the input file is also provided. The best way to understand the program is to browse through the examples.
If you have questions about the capabilities or limitations of the program please contact either Jeff Errington or Thanos Panagiotopoulos.