Hallo,
by looking at some log-files, I found that the total energy of an equivalent bulk calculation of some device may increase.
Example:
| 0 E = -904.874 dE = 1.000000e+00 dH = 9.362434e+00 |
| 1 E = -903.713 dE = 1.161121e+00 dH = 3.644521e+01 |
| 2 E = -898.428 dE = 5.284778e+00 dH = 3.990358e+01 |
| 3 E = -896.109 dE = 2.318983e+00 dH = 1.527096e+01 |
| 4 E = -893.962 dE = 2.147338e+00 dH = 8.132774e+00 |
| 5 E = -890.87 dE = 3.091237e+00 dH = 5.594138e+00 |
| 6 E = -889.498 dE = 1.372694e+00 dH = 6.958408e+00 |
| 7 E = -883.724 dE = 5.773526e+00 dH = 3.347557e+00 |
| 8 E = -879.77 dE = 3.954026e+00 dH = 1.352267e+00 |
| 9 E = -878.238 dE = 1.532401e+00 dH = 4.426615e-01 |
| 10 E = -877.531 dE = 7.072604e-01 dH = 3.419547e-01 |
| 11 E = -876.972 dE = 5.589668e-01 dH = 4.139195e-01 |
| 12 E = -877.276 dE = 3.039722e-01 dH = 1.714145e-01 |
| 13 E = -876.732 dE = 5.437031e-01 dH = 3.740001e-01 |
| 14 E = -876.32 dE = 4.116571e-01 dH = 2.179601e-01 |
| 15 E = -876.591 dE = 2.711817e-01 dH = 2.163622e-01 |
| 16 E = -875.904 dE = 6.871625e-01 dH = 1.749267e-01 |
| 17 E = -875.692 dE = 2.124245e-01 dH = 3.310757e-01 |
| 18 E = -875.051 dE = 6.406186e-01 dH = 3.007363e-01 |
| 19 E = -874.876 dE = 1.756545e-01 dH = 8.158286e-02 |
| 20 E = -874.92 dE = 4.485747e-02 dH = 6.167444e-02 |
...
Convergence is fine, but why does the energy increase? Is this physically meaningful? To my knowledge we search for the ground state energy that should be a global minimum. I know that there may be iteration steps when the energy goes up, but in the above example it looks rather systematic.
