35 ORBITAL MERGING

Orbitals can be manipulated using the MERGE facility. For instance, this allows the construction of molecular orbitals from atomic orbitals, to merge and orthogonalize different orbital sets, or to perform $2\times 2$ rotations between individual orbitals. Other orbital manipulations can be performed using the LOCALI program (see section 15) or the MATROP program (section 32).

The merge program is called using

MERGE[,namout.file]

All subcommands described in the following sections may be abbreviated by three characters. namout.file specifies the output data set (see also SAVE command). If namout.file is omitted and no SAVE card is present, the new orbitals are not saved. All output orbitals must be supplied via ORBITAL and ADD, MOVE, EXTRA, or PROJECT directives before they can be saved.