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You have to generate cartesian coordinates (file `coord`),
nothing else. You can start an single-point calculation calculation
by typing
`uff`

To start an `uff` geometry optimization, one has to change the number
of cycles (parameter `maxcycle`

) in the block `$uff` in the
file `control`. The ouput is the optimized structure (file
`coord`), the analytical gradient (file `uffgradient`)
and the analytical cartesian hessian (file `uffhessian0-0`).
Furthermore the `control` file will be modified:
$forceinit on
carthess
$uffhessian file=uffhesian0-0

These commands have the effect to inititialize the force constant matric for a
geometry optimization with the hessian one.
In some cases `uff` cannot recognize the connectivity, then one can
specify the connectivity in the file `ufftopology`. The program
will calculate the bond, angle, torsion, inverison and non-bonded
terms (force field terms) based on the connectivity specified in the
topology file.

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