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Interconversion Between Internal and Cartesian Coordinates

The interconversion between internal and Cartesian coordinates is not possible directly (in this direction). Instead it is performed iteratively. The following options control this conversion:

interconversion options for RELAX
option    | description
on        | switch on interconversion (DEFAULT: off)
qconv <r> | set convergence threshold for interconversion
          | of coordinates to <r>. DEFAULT : <r> =  .1000E-09
iter <i>  | allow at most <i> iterations for interconversion
          | of coordinates. DEFAULT : <i> =   25
crtint    | transform cartesian into internal coordinates (DEFAULT=n)
intcrt    | transform internal into cartesian coordinates (DEFAULT=n)
grdint    | transform cartesian into internal gradients (DEFAULT=n)
hssint    | transform cartesian into internal hessian (DEFAULT=n)
use -<opt> for disabling any interconversion option

The options qconv and iter are used in each normal relax run to determine the characteristics of the back-transformation of coordinates into the internal space. With the other options and interconversion switched on, you can force relax to perform only the specified coordinate transformation and write the transformed coordinates to file control. To achieve this, enter on to switch to the transformation-only mode, and one of the last four options, e.g. crtint, to specify the desired transformation.