Last Modified 17 Dec 1999
First we need to find the equilbrium lattice constant, then the bulk modulus at that point. We start by looking in a neighborhood around the experimental equlibrium lattice constant, then performing a Birch fit to get the Tight-Binding equilibrium lattice constant. For more information on how to do this, see Example 1.
Since you may want to use a different k-point set for these calculations, this page also provides links to the appropriate sections of the K-point page.
| System | fcc Pt | bcc W | s.c. Ru |
| Parameter file | pt_par | w_par | ru_par |
| Space Group | Fm(-3)m (#225) | Im(-3)m (#229) | Pm(-3)m (#221) |
| Input Files | |||
| Space group file (Cartesian) | spcgrp | spcgrp | spcgrp |
| SKIN file | SKIN | SKIN | SKIN |
| K-points used: | regular.08 | regular.08 | regular.04 |
| More Regular K-point meshes | |||
| Mesh 04 | regular.04 | regular.04 | regular.04 |
| Mesh 06 | regular.06 | regular.06 | regular.06 |
| Mesh 08 | regular.08 | regular.08 | regular.08 |
| Mesh 10 | regular.10 | regular.10 | regular.10 |
| Mesh 12 | regular.12 | regular.12 | regular.12 |
| Mesh 14 | regular.14 | regular.14 | |
| Mesh 16 | regular.16 | ||
| Output Files (Text) | |||
| SKENG file | SKENG | SKENG | SKENG |
| Graphical Output Files | |||
| GNUPLOT ``fitting'' file | ptfit.gnu | wfit.gnu | rufit.gnu |
| GNUPLOT ``ploting'' file | ptplot.gnu | wplot.gnu | ruplot.gnu |
| GNUPLOT output (PNG file) | pt.png | w.png | ru.png |
| Birch Fit Results | |||
| Equilibrium Lattice Constant (Bohr) | 7.38 | 5.93 | 4.69 |
| Equilibrium Volume (Bohr3) | 100.6 | 104.1 | 102.9 |
| Equilibrium Energy (mRy) | -0.76 | 0.61 | 97.69 |
| Bulk Modulus (GPa) | 319 | 319 | 218 |
| Work Directory | pt/bulk | w/bulk | ru/bulk |
Cubic Elastic Constant Home Page
Look at other examples.
Get other parameters from the Tight-binding periodic table.
Return to the static Reference Manual.