[gmx-users] a way to constraint molecules(make rigid CS2)

[조주연]

Dear gromacs users
i want to get a Raman spectrum of CS2 molecules(carbon disulfides)
for that, first i want to run MD of rigid CS2
so i searched about how to constraint bond lengths and angles
i found that in a itp file, [constraint] section i can fix bond lengths but i couldnt find how to fix angles
i searched and searched, finally i got a this answer from gmx-users list about 3years ago
http://www.mail-archive.com/gmx-users@gromacs.org/msg22843.html
there, it says the best way to handle linear rigid molecules in gromacs is  using virtual sites
is this still the best way to make linear rigid molecules?
if someone answers, i will appreciate so much.