[gmx-users] LJ parameters

[Valentin Gogonea]

Thank you Erik,

So if there is no parameters in the [nonbond_params] section for an A-B 
type interaction, the parameters from  [atomtypes] section will be 
combined to produce A-B type parameters by default?

Valentin

On Thursday, May 23, 2002, at 06:18 PM, Erik Lindahl wrote:

> Valentin Gogonea wrote:
>
>> Dear Gromacs users,
>>
>> There are LJ c6 and c12 parameters both in [atomtypes] and 
>> [nonbond_params] sections of ffgmxnb.itp file. Which of them are used 
>> and under what circumstances? Is this described somewhere in the 
>> manual?
>
> Check the topology section;
>
> In short, the parameters in [atomtypes] are the default ones for each 
> atom species (e.g. A-A or B-B interaction). When we have combinations 
> like A-B you can either use combination rules, or explicitly specify 
> the parameters to use for e.g. A-B interactions.
>
> The same thing goes for [ pairtypes ] (i.e. 1,4 - interactions). They 
> can be generated by scaling the normal parameters (fugde factors), or 
> you can specify them manually.
>
>
> Cheers,
>
> Erik
>
>