Output for use by Tripos's SYBYL program can be generated by use of SYBYL. This requires a minimum of at least one SCF calculation to be done, in order to calculate the heat of formation, partial charges, HOMO and LUMO energies. A normal output is also required, so SYBYL should not be used with keywords that prevent normal output, i.e., it should not be used with FORCE, STEP, DRC, etc.