real(dp),parameter:: g(4,4)=reshape((
     & /-1._dp,0._dp ,0._dp , 0._dp,
     &  0._dp ,-1._dp,0._dp , 0._dp,
     &  0._dp , 0._dp,-1._dp, 0._dp,
     &  0._dp,  0._dp, 0._dp,+1._dp/),(/4,4/))