INTEGER nipass,ipass
DO ipass=1,nipass
passkey = ipass + (k-1) *maxcube
IF (ipass.EQ.1) THEN
ELSEIF (ipass.EQ.2) THEN
calc_fluxes_X = MOD(ipass,2).EQ.1
& ( overlapOnly .OR. ipass.EQ.1 ) ) THEN
IF ( overlapOnly .AND. ipass.EQ.1 ) THEN