QMMM setting up

[Matt W]

Normally you'd specify the radius of the MM_KINDS - this defines the width 
of the gaussian(s) the charge is broadened to for calculating the QM/MM 
electronic coupling - probably it would be something like a covalent/ionic 
radius, but in principle is a parameter that should be optimized for your 
system.

You can ignore the force_mixing stuff.

Matt 

On Friday, August 28, 2015 at 2:04:12 PM UTC+1, Geng Sun wrote:
>
> Matt,
>
>     Thanks for the specification. 
>
>     But  I still have several other questions.
>
>     1) In the part of FORCE_EVAL 
> <http://manual.cp2k.org/cp2k-2_6-branch/CP2K_INPUT/FORCE_EVAL.html> / 
> SUBSYS 
> <http://manual.cp2k.org/cp2k-2_6-branch/CP2K_INPUT/FORCE_EVAL/SUBSYS.html>
>  / KIND 
> <http://manual.cp2k.org/cp2k-2_6-branch/CP2K_INPUT/FORCE_EVAL/SUBSYS/KIND.html> section, 
> should I set all the types of atoms in both QM_KINDS and MM_KINDS, or just 
> in QM_KINDS ?
>
>      2) And,  The section of FORCE_EVAL 
> <http://manual.cp2k.org/cp2k-2_6-branch/CP2K_INPUT/FORCE_EVAL.html> / QMMM 
> <http://manual.cp2k.org/cp2k-2_6-branch/CP2K_INPUT/FORCE_EVAL/QMMM.html>
>  / FORCE_MIXING 
> <http://manual.cp2k.org/cp2k-2_6-branch/CP2K_INPUT/FORCE_EVAL/QMMM/FORCE_MIXING.html>, 
> which uses the method of [Bernstein2012 
> <http://manual.cp2k.org/cp2k-2_6-branch/references.html#reference_106>] 
> is the place to set the adaptive QMMM method. If I don't want to use that 
> method,
>
>   I could just leave this section not been used. At this momenta, the 
> numbers of atoms in QM and MM parts do not change during simulation. Am I 
> right ?. 
>
>   If I do not use the force_mixing scheme, the total energy 
> E=E(qm)+E(mm)+E(qm-mm). The forces are the derivatives of the energy, so 
> the energy should be  conservative in principle rather than in the 
> force_mixing scheme. Do I understand correctly ?
>
>   Thanks in advance
>
>    Geng Sun
>
>
>>>
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