INQUIRE(FILE='OPTCELL',EXIST=FILFLG)
IF (FILFLG) THEN
OPEN(67,FILE='OPTCELL',FORM='FORMATTED',STATUS='OLD')
READ(67,"(3I1)") (ICELL(I),I=1,3)
CLOSE(67)
DO I=1,3
SAVE(I)=FCELL(I,I)
ENDDO
FCELL=0.0d0
DO I=1,3
IF (ICELL(I)==1) FCELL(I,I)=SAVE(I)
ENDDO
ENDIF
! just one simple example
! relaxation in x directions only
! SAVE=FCELL(1,1)
! FCELL=0 ! F90 style: set the whole array to zero
! FCELL(1,1)=SAVE