Optimized extended JCZ3 procedures which have been implemented through the “JAGUAR” computer routines result in accurate detonation properties for wide ranges of conditions including the C-J state and high volume expansions. In order to obtain improved results at highly overdriven conditions, optimized EXP-6 parameters have been established for formic acid by the use of experimental Hugoniot data for PBX-9501. The procedures of this study enable the highly accurate calculation of detonation properties of explosives for a very wide range of volumes. ©2000 American Institute of Physics.