Keywords used in MOPAC data sets to define Reference Data

Reference data are defined in normal MOPAC data sets.  Each dataset describes a single system, such as cesium in the 2P state, (an excited state),  water (a molecule), NO (a radical), sodium sulfate anion, [NaSO4]-, an anion, etc.  The values of all reference data, except geometric, are given on Line 3 of a MOPAC data set.  For geometric reference data, the reference values (bond lengths and angles) are given in the Z-matrix.

Text on Line 3 is not used by MOPAC, but is used by PARAM.

<> A geometric parameter is not to be used as a reference
<text> A geometric parameter is to be used as a reference
D=n.nn The reference dipole moment is defined as n.nn
DR=<text> The reference dipole source is given by the mnemonic <text>
DWT=n.n The default reference dipole moment weight is to be multiplied by n.n
GR=<text> The reference geometry source is given by the mnemonic <text>
GWT=n.n The default reference geometry weight is to be multiplied by n.n
H=n.nn The reference Heat of Formation is defined as n.nn
H=n.nn+<text> The reference Heat of Formation is defined as n.nn relative to ,text>
HR=<text> The reference Heat of Formation source is given by the mnemonic <text>
HWT=n.n The default reference Heat of Formation weight is to be multiplied by n.n
I=n.nn The reference Ionization Potential is defined as n.nn
IR=<text> The reference Ionization Potential source is given by the mnemonic <text>
IWT=n.n The default reference Ionization Potential weight is to be multiplied by n.n
ROOT=<text>

A named electronic state is to be used