FORCE,NUMERICAL,STARTCMD=command
where command is the first command in the input needed for the current energy calculation. The command must be found in the input before the FORCE card, i.e., the sequence of input cards starting with command and ending with FORCE is used to compute the energies. For example, in order to compute numerical gradients for ccsd(t), it is necessary to do a HF and a CCSD(T) calculation at each geometry. The input would read
hf ccsd(t) forces,numerical,startcmd=hf
The program will then automatically repeat HF and CCSD(T) at as many geometries as needed for evaluating the gradient. The keyword NUMERICAL implies that also STARTCMD must be given, otherwise an error results.