Biharmonic Function

For POTEntial=BIHArmonic, a two-sided harmonic function is used:
\begin{displaymath}
E_{NOE}^{class} = {\rm min}(ceil, \frac{SK_{b}T}
{2c^{2}_{ij}})
\quad (R-d)^{2}
\end{displaymath} (20.7)


\begin{displaymath}
c_{ij} = \left\{ \begin{array}{ll}
d_{minus} & \mbox{$R < d$} \\
d_{plus} & \mbox{$R > d$}
\end{array}
\right.
\end{displaymath} (20.8)

where $S$ is the scale factor specified by the SCALe statement, $K_{b}$ is the Boltzmann constant, $T$ is the temperature specified by the TEMPerature statement, $ceil$ is specified by the CEILing statement, $d$, $d_{plus}$, and $d_{minus}$ are specified by the ASSIgn statement:

\begin{eqnarray*}
{\tt assign \quad <selection> \quad <selection> }
\quad d \quad d_{minus} \quad d_{plus}
\end{eqnarray*}


The distance $R$ is defined in Section 20.2. The deviation $\Delta$ is defined as $\vert R-d\vert$.



Xplor-NIH 2023-11-10