IF (.NOT.useMATRIX) THEN
LOGICAL useMATRIX
& usePTRACERS, useGCHEM, useRBCS, useOffLine, useMATRIX,
IF (useMATRIX)
IF ( useMATRIX ) CALL MATRIX_INIT( myThid )
IF ( useMATRIX .AND. useGCHEM ) THEN
IF ( useMATRIX .AND. .NOT.usePTRACERS ) THEN
IF (useMATRIX) CALL MATRIX_READPARMS ( myThid )
IF (useMATRIX) CALL PACKAGES_CHECK_ERROR('MATRIX', myThid)
useMATRIX =.FALSE.
& useMATRIX,