Optimization of one unknown

If a system has exactly one coordinate to be optimized, then obviously one line-search will optimize the geometry. Because of this, the geometry optimization is done a little differently. Given the initial geometry, the ΔHf  is calculated, and the line-search started. Unlike the normal line-search, however, the search is not stopped when the minimum is almost reached, instead, the minimum is located with quite high precision. After the line-search is complete, the gradients are not   calculated (unless requested by GRADIENTS). Instead, it is assumed that the gradient is small, and the results are output. This saves some time. However, if GRADIENTS is not present, and the geometry is not at a stationary point (because other coordinates are not optimized), then the warning message that the geometry is not at a stationary point will not be printed.