I have calculated the dependence of (1/s11) ie. single-crystal young's modulus on crystallographic direction for an inorganic crystal. I've noticed that certain peaks correspond to closely-packed planes eg. a psedo-hexagonal arrangement is seen in directions where the peaks (ie. local maxima) for (1/s11) occur. I wonder if one can immediately conclude that the strength of the bonding and/or peak in the young's modulus is due to the way the atoms are packed. Any comments?