GSAS: lessen the tedium: batch file control of the refinement :(EXPEDT Example: refine oxygens)
 
 
k            ! don't make a backup of the file
v 1:324 -x   ! get rid of any X parameters refining
v 1:324 -u   ! get rid of any UISO parameters refining
v 1:324 -f   ! get rid of any FRAC parameters refining
v 163:324 x  ! set oxygens to refine