MOLPRO

3 DEFINITION OF MOLPRO INPUT LANGUAGE 9
As already mentioned, the use of curly brackets is normally compulsary if more than one input
line is needed. In the case of one-line commands, curley brackets are needed as well if the next
command or procedure has the same name as a directive valid for the current command.
Note: DIRECT and associated options cannot be specified on command lines any more.
3.3 Directives
Directives serve to specify input data and special options for programs. They start with a keyword,
followed by data and/or options. The general format is
DIRECTIVE,data,options
The format of data and options is specified in the subsequent sections. Data must always be
given before any options.
Examples for directives are
OCC,CORE, CLOSED, WF, LOCAL, DFIT, . . .
3.4 Global directives
Certain directives can be given anywhere in the input, i.e. either inside or outside command
blocks. If they are given inside of command blocks, the specified options are valid only locally
for the current program. However, if they are given outside a command block, they act globally,
and are used for all programs executed after the input has been encountered. Local options have
preference over global options.
The following directives can be either local or global:
Wavefunction definition: OCC,CORE, CLOSED, FROZEN, WF
Thresholds and options: LOCAL, DFIT, DIRECT, EXPLICIT, THRESH, PRINT, GRID
If such options are given outside a command block, a context can be specifified
DIRECTIVE,data,CONTEXT=context,
e.g.,
OCC,3,1,1,CONTEXT=HF
OCC,4,1,2,CONTEXT=MCSCF
CONTEXT can be any valid command name (or any valid alias for this), but internally these are
converted to one of the following: HF (Hartree-Fock and DFT), MC (MCSCF and CASSCF),
CC (single reference correlation methods, as implemented in the CCSD program), CI (multireference
correlation methods, as implemented in the MRCI program). The directive will then be
applied to one of the four cases. Several contexts can be specified separated by colon, e.g.,
CONTEXT=HF:CCSD
If only a single context is given (no colon), shortcuts for the specifying the CONTEXT option
are obtained by postfixing context to the command name, e.g.,
OCC HF,3,1,1
OCC MCSCF,4,1,2
If no context is given, the default is HF. The default occupations for single reference methods
(e.g., MP2, CCSD) are the ones used in HF, the defaults for multireference methods (e.g. RS2,
MRCI) correspond to those used in MCSCF.