Defining mass center of a pull group

GROMACS version: 2022
GROMACS modification: /No
Dear all,
In order to define a mass center I have used pull-group1-weights = 165, where 165 is the number of atoms in the pull group. In gromacs-2022 manual it is mentioned that it is " Optional relative weights which are multiplied with the masses of the atoms to give the total weight for the COM. The number should be 0, meaning all 1, or the number of atoms in the pull group". This is confusing. Moreover when I am asigning this parameter it is showing the following error
Fatal error:
Number of weights (1) for pull group 1 ‘UL-O’ does not match the number of
atoms (165)
The comments from the user and developers is highly necessary to solve the issue.

Hi,
My understanding is that
to pull-group1-weights option you can provide the relative weight you want for each atom of the pull group
For example if you have a pull group of 6 atoms and you want that the weight of the first 3 atom is multiplied by 0.5 and the other by 1 then
pull-group1-weights = 0.5 0.5 0.5 1 1 1

/Alessandra

Thanks for your reply