Alternative Hamiltonian for molecular dynamics simulations in the grand canonical ensemble

An alternative to the Hamiltonian of Cagin and Pettitt for performing molecular dynamics simulations in the grand canonical ensemble is presented and used as the basis for a new algorithm. The algorithm is tested on the ideal gas and the truncated and shifted Lennard‐Jones fluid. Simulations are used to calculate the vapor–liquid coexistence points for the Lennard‐Jones system and are found to be in agreement with previous calculations using Gibbs ensemble calculations and with the Nicolas equation of state. Simulations are also performed on the Lennard‐Jones solid.