Nb fcc LJ_ElliottAkerson_2015_Universal__MO_959249795837_003 4.51086205244 Warning: Maximum number of function evaluations has been exceeded. C11 = 3503.628568 +/- 0.007336 GPa C12 = 1998.974310 +/- 0.005187 GPa C44 = 2003.129101 +/- 0.001834 GPa B = 2500.525729 +/- 0.004235 GPa