Enter a species  (e.g. Al, Fe): Si
Enter a hexagonal lattice type (e.g. hcp): hcp
Enter a model name: ThreeBodyCluster_Gong_Gong_1993_Si__MO_407755720412_000
Enter hexagonal lattice constants 'a' and 'c' (m): 2.788106913971087e-10, 4.358895538071596e-10

Calculating isothermal bulk modulus

Optimization terminated successfully.
         Current function value: -13.293477
         Iterations: 72
         Function evaluations: 191

Finished calculation

C11 = 935.6489892839833 GPa
C12 = 464.0030663837137 GPa
  B = 621.2183740171369 GPa