potfit wiki

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~~NOTOC~~
====== EAM + electrostatic potential ======
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//**Info:**//
This page is incomplete and may contain invalid/wrong information!
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The EAM + electrostatic potential is a combination of the regular EAM model with an additional coulomb term.

$$
E_{tot}=E_{EAM} + \frac{1}{2} \sum_{i\neq j} E(r_{ij}) \quad \text{with} \quad
E(r_{ij}) \sim \frac{q_{i}q_{j}}{r_{ij}}
$$
=====  Number of potential functions  =====

To describe a system with $N$ atom types you need $N(N+5)/2$ potentials.

^ # atom types ^ $\Phi_{ij}$ ^ $\rho_j$ ^ $F_i$ ^ Total # potentials ^
^ $N$ ^ $N(N+1)/2$ ^ $N$ ^ $N$ ^ $N(N+5)/2$ ^
| 1 | 1 | 1 | 1 | 3 |
| 2 | 3 | 2 | 2 | 7 |
| 3 | 6 | 3 | 3 | 12 |
| 4 | 10 | 4 | 4 | 18 |

=====  Order of potential functions  =====

The potential table is assumed to be symmetric, i.e. the potential for the atom types 1-0 is the same as the potential 0-1.

The order of the EAM potentials in the potential file for //N// atom types is:

$\Phi_{00}, \ldots, \Phi_{0N}, \Phi_{11}, \ldots, \Phi_{1N}, \ldots, \Phi_{NN},$\\
$\rho_0, \ldots, \rho_N,$\\
$F_0, \ldots, F_N,$