[gmx-users] 6-31G** for Gromacs

[ilona.baldus at bioquant.uni-heidelberg.de]

Hi Gerrit,

I would like to use 6-31G** for my QMMM-calculation. Since sulfur is  
part of my QM system, I consider that a sensible thing to do.  
Unfortunately, it is not implemented in Gromacs, so I tried to add  
that bit myself.

Here's the point where I got stuck:
  src/mdlib/qm_gaussian.c translates the basis set is converted via  
"ivec" to some number format for gaussian (line 75-84). How did you  
get the numbers in {} and what do they mean?

The other part where I am insecure is include/types/enums.h, line 199-203:

enum {
   eQMbasisSTO3G, eQMbasisSTO3G2, eQMbasis321G,
   eQMbasis321Gp, eQMbasis321dGp, eQMbasis621G,
   eQMbasis631G, eQMbasis631Gp, eQMbasis631dGp,
   eQMbasis6311G, eQMbasisNR
};

Obviously, names are just listed here, so I think of just adding  
"eQMbasis631Gdp" for 6-31G** which is equal to 6-31G(d,p). Would that  
conflict with eQMbasis631dGp which stands for 6-31+G* ?

Thanks in advance,

Best wishes, Ilona