[gmx-users] LJ values conversion

[라지브간디]

Thanks for the mail justin.


In charmm27.ff, the value for bonded are in b0 and ko format, whereas the gromos uses them in different way? If so, how do i convert between them? 


The value i incorporated for specific atoms are from published journals. Thanks in advance.


 
On 3/27/13 2:15 AM, ��������������� wrote: 
> Hello gmx, 
> 
> 
> I have LJ parameter value of C (epsilon = 0.0262 kcal/mol, sigma = 3.83) O (epsilon = 0.1591. sigma = 3.12) in charmm format and wants to use them in gromos43a1 or charmm27 force field in gromacs. 
> 
> 
> Could you tell me how do i convert them to gromacs format? Any examples plz. 
> 
> 

Equation 5.1 in the manual, or apply g_sigeps. Note that picking values of 
atoms randomly and inserting them into an existing force field is a great way to 
completely invalidate the force field. Atom types are balanced against one 
another. Making ad hoc changes means you're using an unvalidated parameter set, 
and any good reviewer is going to have serious issues with whatever data you 
produce. 

-Justin