Properties of real metallic surfaces: Effects of density functional semilocality and van der Waals nonlocality. Density Functional Theory: A Practical Introduction.“First principles methods using CASTEP” Zeitschrift fuer Kristallographie 220(5-6) pp.With better computational ability, these results should be checked against varying layers for the surface calculations as well as a higher ENCUT for both the bulk calculation and the surface calculations. This result shows that the (111) surface is the preferred face for crystal growth. In previous comparisons against multiple functionals, the percentage difference was lower. The energy of the (111) surface is found to be 15% lower than the (100) surface. The results are in agreement with the known result that says that the (111) surface is energetically favorable to the (100) surface of Ag. This gave the following results for the surface energy densities: The change in energy from the previous k-point energy calculation. For all the rest of the options, the defaults were used. We use inverse Wulff construction, based on nonlinear optimization and crystal symmetries, to acquire surface energies from Wulff shapes. The convergence tolerances were chosen somewhat arbitrarily to be small: energy at 2.0e-5 eV/atom, force at 0.05 eV/Å, stress at 0.1 GPa, and displacement at 0.002 Å. Ag has the electron configuration of 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s1, and the pseudopotential treats 4s2 4p6 4d10 5s1 as the valence electrons. Using CASTEP with the GGA PBE functional and OTFG ultrasoft pseudopotentials, we run through different energy cutoffs to find an appropriate energy cutoff for energy convergence. So for both 100 and 111 surfaces, we need to calculate the energy of bulk Ag. Surface Energy Calculationįirst, in order to calculate the surface energy for a particular surface, we need to refer to the following equation found in “Density Functional Theory : A Practical Introduction”: Note that silver is an FCC crystal with a lattice constant of 4.09 Å and that this experimental result will be used in the calculations. The results are in agreement with the known result 4 that says that the (111) surface is energetically favorable to the (100) surface of Ag. This gave the following results for the surface energy densities: Conclusion. These properties can reveal the preferred behavior in surface Ag formation. The following Energies were found: -28043.265 and -28043.196.
#Silver surface energy wulff construction wolfram player software#
In this post, we will use DFT calculations using CASTEP software to calculate the energy of bulk silver as well as relaxing a cleaved surface. We will investigate some properties of crystalline silver: the relative surface energies for the 100 and 111 cleaved faces.
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