SPRING K: Difference between revisions
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{{TAGDEF|SPRING_K|[real (array)]}} | {{TAGDEF|SPRING_K|[real (array)]}} | ||
Description: The parameter {{TAG|SPRING_K}} defines force constants (<math>\kappa_{\mu})</math> for the harmonic bias | 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 \; | ||
Revision as of 08:25, 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.