SPRING K: Difference between revisions
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Description: The parameter {{TAG|SPRING_K}} defines force constants (<math>\kappa_{\mu})</math> for the harmonic bias of the following form: | Description: The parameter {{TAG|SPRING_K}} defines force constants (<math>\kappa_{\mu})</math> for the harmonic bias of the following form: | ||
<math> | <math> | ||
\tilde{V}(\xi_1,\dots,\xi_{M_8}) = \sum_{\mu=1}^{M}\frac{1}{2}\kappa_{\mu} (\xi_{\mu}(q)-\xi_{0\mu})^2 \; | \tilde{V}(\xi_1,\dots,\xi_{M_8}) = \sum_{\mu=1}^{M}\frac{1}{2}\kappa_{\mu} (\xi_{\mu}(q)-\xi_{0\mu})^2 \; | ||
</math> | </math> | ||
where the sum runs over all (<math>M_8</math>) coordinates the potential acts upon (<math>\xi_{\mu}(q)</math>), which are defined in the {{FILE|ICONST}}-file by setting the <code>status</code> to 8. | where the sum runs over all (<math>M_8</math>) coordinates the potential acts upon (<math>\xi_{\mu}(q)</math>), which are defined in the {{FILE|ICONST}}-file by setting the <code>status</code> to 8. | ||
The units of <math>\kappa_{\mu}</math> are <math>eV/uc</math> where <math>uc</math> units of coordinate the potential acts upon (e.g., <math>{\AA}</math> for coordinates with <code>flag</code> R, <math>rad.</math> for coordinates with <code>flag</code> A, dimensionless for coordinates with <code>flag</code> W, etc...) | The units of <math>\kappa_{\mu}</math> are <math>eV/uc</math> where <math>uc</math> units of coordinate the potential acts upon (e.g., <math>{\AA}</math> for coordinates with <code>flag</code> R, <math>rad.</math> for coordinates with <code>flag</code> A, dimensionless for coordinates with <code>flag</code> W, etc...) | ||
Revision as of 08:43, 11 April 2023
SPRING_K = [real (array)]
Description: The parameter SPRING_K defines force constants ([math]\displaystyle{ \kappa_{\mu}) }[/math] for the harmonic bias of the following form:
[math]\displaystyle{ \tilde{V}(\xi_1,\dots,\xi_{M_8}) = \sum_{\mu=1}^{M}\frac{1}{2}\kappa_{\mu} (\xi_{\mu}(q)-\xi_{0\mu})^2 \; }[/math]
where the sum runs over all ([math]\displaystyle{ M_8 }[/math]) coordinates the potential acts upon ([math]\displaystyle{ \xi_{\mu}(q) }[/math]), which are defined in the ICONST-file by setting the status to 8.
The units of [math]\displaystyle{ \kappa_{\mu} }[/math] are [math]\displaystyle{ eV/uc }[/math] where [math]\displaystyle{ uc }[/math] units of coordinate the potential acts upon (e.g., [math]\displaystyle{ {\AA} }[/math] for coordinates with flag R, [math]\displaystyle{ rad. }[/math] for coordinates with flag A, dimensionless for coordinates with flag W, etc...)
The number of items defined via SPRING_K must be equal to [math]\displaystyle{ M_8 }[/math], otherwise the calculation terminates with an error message.