Recent studies showed that hardness, a complex property, can be calculated using very simple approaches or even analytical formulae. These form the basis for evaluating controversial experimental results (as we illustrate for TiO2-cotunnite) and enable a systematic search for novel hard materials, for instance, using global optimization algorithms (as we show on the example of SiO2 polymorphs).
@article{arxiv.1009.5477,
title = {Towards the theory of hardness of materials},
author = {A. R. Oganov and A. O. Lyakhov},
journal= {arXiv preprint arXiv:1009.5477},
year = {2010}
}