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