Example: A Conditional Test

This example either divides or multiplies the symbol $1 by a factor of two, depending on the value of the NOE energy ($NOE). In the first case, 40 steps of minimization are carried out, whereas in the latter case, 100 steps of minimization are carried out. Note that the indentation is arbitrary but can make the input file more readable.

if ($NOE > 10.0) then 
   evaluate ($1=$1/2.0) 
   minimize powell
     nstep=40 
  end
else
   evaluate ($1=$1*2.0)
   minimize powell
     nstep=100 
   end
end if