Input Data Blocks Needed by RELAX

`$intdef`or`$redundant`-

Definitions of internal coordinates and, optionally, values of internal coordinates (`val=...`

, given in a.u. or degrees) or force constant diagonal elements (`fdiag=...`

). `$grad`-

Cartesian coordinates and gradients calculated in subsequent optimization cycles. Entries are accumulated by one of the gradient programs (`grad`,`mpgrad`,`rimp2`,`ricc2`,`egrad`, etc.). `$egrad`-

Basis set exponents scale factors and their gradients as calculated in subsequent optimization cycles. Entries are accumulated by one of the gradient programs. `$globgrad`-

Global scale factors and gradients as calculated in subsequent optimization cycles. Entries are accumulated by the`grad`or`aoforce`program. `$corrgrad`-

Allows to augment internal SCF gradients by approximate increments obtained from treatments (e.g. correlation or relativistic) on higher level. See the example below.$corrgrad # coordinate increment 1 0.0600 8 -0.0850

`$forceapprox`*options*-

Approximate force constant matrix (as needed for geometry optimization tasks). The storage format may be specified by the

available options:`format=`*format*-

the default format is`format=(8f10.5)`

, but other 10-digit f10.x formats (e.g. x=4,6,..) are possible and will be used, after being manually specified within`$forceapprox`. See the example below:$forceapprox format=(8f10.4) 0.9124 -.0108 0.3347 0.2101 0.0299 1.3347 0.0076 0.1088 0.0778 0.6515

`$hessian (projected)`-

this data block contains the analytical cartesian force constant matrix (with translational and rotational combinations projected out) as output by the`aoforce`program and may be used to supply a high quality force constant matrix`$forceapprox`for geometry optimizations (specifying`$forceinit on carthess`, or`$interconversion cartesian -> internal hessian`).