MOLPRO

6 PROGRAM CONTROL 34
6.7.1 IF statements
IF blocks have the same form as in Fortran:
IF (logical expression) THEN
statements
ENDIF
If only one statement is needed, the one-line form
IF (logical expression) statement
can be used, except if statement is a procedure name.
ELSE and ELSE IF can be used exactly as in Fortran. IF statements may be arbitrarily nested.
Jumps into IF or ELSE IF blocks are allowed. In this case no testing is performed; when an
ELSE is reached, control continues after ENDIF.
The logical expression may involve logical comparisons of algebraic expressions or of strings.
Examples:
IF(STATUS.LT.0) THEN
TEXT,An error occurred, calculation stopped
STOP
ENDIF
IF($method.eq.’HF’) then
...
ENDIF
In the previous example the dollar and the quotes are optional:
IF(METHOD.EQ.HF) then
...
ENDIF
6.7.2 GOTO commands
GOTO commands can be used to skip over parts of the input. The general form is
GOTO,command,[n],[nrep]
Program control skips to the |n|’th occurrence of command (Default: n = 1). command must be
a keyword in the first field of an input line. If n is positive, the search is forward starting from
the current position. If n is negative, search starts from the top of the input. The GOTO command
is executed at most nrep times. The default for nrep is 1 if n < 0 and infinity otherwise. We
recommend that GOTO commands are never used to construct loops.
Alternatively, one can jump to labels using
GOTO,label
Since labels must be unique, the search starts always from the top of the input. It is required that
the label ends with a colon.