Pseudoexperimental data of high accuracy on the pressure and the inter
nal energy of the Lennard-Jones fluid have been generated both by the
Monte Carlo and molecular dynamics methods for five subcritical and th
ree supercritical isotherms. Values of the chemical potential of the L
ennard-Jones fluid computed by a new version of the gradual insertion
particle method for two isotherms up to very high densities are also r
eported and discussed, and compared with existing data.