NEGATIVE_AIJThis command tests all edges of all boundary faces for negative coupling coefficients.
neg_coup_coeff, type=VDOUBLE, length=num_neg_coup_coeff  value of coupling coefficient
ietet_aij, type=VINT,
length=num_neg_coup_coeff,rank=vector

for each negative coupling coefficient,
i: ietet_aij(1,i)
contains
the tetrahedron number which contributes the most negative portion to the
coupling coefficient, ietet_aij(2,i)
contains
the local face number that contains the local edge (ietet_aij(3,i))
which
has the negative coupling coefficient