SPRING_K

SPRING_K = [real (array)]

Description: Force constant for harmonic bias potential.

The parameter SPRING_K defines force constants ( $\kappa _{\mu }$ ) for the harmonic bias of the following form:

{\tilde {V}}(\xi _{1},\dots ,\xi _{M_{8}})=\sum _{\mu =1}^{M}{\frac {1}{2}}\kappa _{\mu }(\xi _{\mu }(q)-\xi _{0\mu })^{2}\;

where the sum runs over all ( $M_{8}$ ) coordinates the potential acts upon ( $\xi _{\mu }(q)$ ), which are defined in the ICONST file by setting the status to 8. The units of $\kappa _{\mu }$ are $eV/uc$ where $uc$ units of coordinate the potential acts upon (e.g., ${\mathrm {\AA} }$ for coordinates with flag R, $rad.$ for coordinates with flag A, dimensionless for coordinates with flag W, etc...) The number of items defined via SPRING_K must be equal to $M_{8}$ , otherwise the calculation terminates with an error message.

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