Togi,
There is a way to get the script to work.
Look at the MOST RECENT Version of the par_all36_cgenff.prm file:
!hydrogens
MASS -1 HGA1 1.00800 H ! alphatic proton, CH
MASS -1 HGA2 1.00800 H ! alphatic proton, CH2
MASS -1 HGA3 1.00800 H ! alphatic proton, CH3
MASS -1 HGA4 1.00800 H ! alkene proton; RHC=
.
.
.
Now look at an older version
!hydrogens
MASS 256 HGA1 1.00800 ! alphatic proton, CH
MASS 257 HGA2 1.00800 ! alphatic proton, CH2
MASS 258 HGA3 1.00800 ! alphatic proton, CH3
MASS 259 HGA4 1.00800 ! alkene proton; RHC=
.
.
.
Notice that in the second column the numbers were replaced by “-”. Each atom type was assigned a number in the older version. But this presented a limitation when a new atom type was to be added because a new atom type needed a unique number.
The “-” replacement allowed more flexibility in the addition of new atom types.
If you can find an older version of the forcefield parameter files, and replace the new files with the old files, the script will work.
Regards,
Angelo