SPRING V0: Difference between revisions

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{{TAGDEF|SPRING_V0|[real (array)]}}
{{TAGDEF|SPRING_V0|[real (array)]}}


Description: The parameter {{TAG|SPRING_V0}} defines the rate at which the position of minimum (<math>\xi_{0\mu}</math>) of the harmonic bias potential of the form:
Description: Consider the bias potential of the form:
<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 \;
</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 status to 8.
Optionally, the position of minimum (<math>\xi_{0\mu}</math>) can be shifted at a constant rate <math>\dot{\xi}_{\mu}</math>, i.e.
<math>
\xi_{0\mu}(t+\Delta t) = \xi_{0\mu}(t)\dot{\xi}_{\mu}(q) \;
</math>
 
 
The parameter {{TAG|SPRING_V0}} defines the rate at which the position of minimum (<math>\xi_{0\mu}</math>) of the harmonic bias potential of the 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 \;
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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 status 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 status to 8.
The units of {{TAG|SPRING_V0}} are <math>uc/fs</math>, where <math>uc</math> corresponds to the units of the 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 {{TAG|SPRING_V0}} are <math>uc/fs</math>, where <math>uc</math> corresponds to the units of the 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 number of items defined via {{TAG|SPRING_V}} must be equal to <math>M_8</math>, otherwise the calculation terminates with an error message.
The number of items defined via {{TAG|SPRING_V0}} must be equal to <math>M_8</math>, otherwise the calculation terminates with an error message.





Revision as of 08:38, 11 April 2023

SPRING_V0 = [real (array)] 

Description: Consider the bias potential of the 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. Optionally, the position of minimum ([math]\displaystyle{ \xi_{0\mu} }[/math]) can be shifted at a constant rate [math]\displaystyle{ \dot{\xi}_{\mu} }[/math], i.e. [math]\displaystyle{ \xi_{0\mu}(t+\Delta t) = \xi_{0\mu}(t)\dot{\xi}_{\mu}(q) \; }[/math]


The parameter SPRING_V0 defines the rate at which the position of minimum ([math]\displaystyle{ \xi_{0\mu} }[/math]) of the harmonic bias potential of the 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] is shifted, 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 SPRING_V0 are [math]\displaystyle{ uc/fs }[/math], where [math]\displaystyle{ uc }[/math] corresponds to the units of the 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_V0 must be equal to [math]\displaystyle{ M_8 }[/math], otherwise the calculation terminates with an error message.


Related tags and articles

SPRING_K SPRING_R0 ICONST Biased molecular dynamics