The STEP size is under user control. Use a value that will allow the potential energy surface to be drawn without having it look too jerky. For the CH3CL stretch example below, the step-size was 0.02 Ångstroms. This gives a nice PES. If a smaller step-size is used, it should still run okay, but the run will take longer, because the number of points needed will be larger.
Example: Stretching a C-Cl bond in CH3Cl. In this example, the C-Cl bond length starts at 1.5 Ångstroms, and stretches by 0.02 Ångstroms at a time to 2.3 Ångstroms.
step=0.02 point=40 CH3Cl Stretching the C-Cl bond Cl 0.00000000 0 0.0000000 0 0.0000000 0 0 0 0 C 1.50000000 -1 0.0000000 0 0.0000000 0 1 0 0 H 1.10153604 1 108.0234648 1 0.0000000 0 2 1 0 H 1.10231454 1 108.0092176 1 120.0000000 1 2 1 3 H 1.10177640 1 107.8415102 1 -120.0000000 1 2 1 3
For an alternative way of defining points on a path, that produces an output similar to the conventional output, see alternative points.