First Attempt

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First optimization: Make some changes to the CNTL file:

Add an !RDYN section, which is similar to the psidyn section, but which will describe the motion of the atomic centers.
Turn on the friction in both sections again, and set them to 0.01, except the high psi friction, which should be set to 0.1. When you remove the OFF option for AUTO, these values now override the constant friction we set previously. We set these lower frictions to allow the centers to relax better.
Set the friction scaling factors to 1., except for the lower R value, which should be 0.95.
Set the number of steps: NSTEP=500
Refer to Figure 8 to see the changes made.
Run the executable again.
Observe the protocol output.
Plot the energies with paw_show as before and observe how the energy changes when, for example, the friction changes.

**Figure:** *h2co.cntl (4)*
$\begin{figure}\begin{small} \begin{tex2html_preform}\begin{verbatim}!CONTROL !G... ... !END !END !END !EOB\end{verbatim}\end{tex2html_preform}\end{small}\end{figure}$

Wun Chiou
2000-03-30