a question about fix shake

LAMMPS LAMMPS Mailing List Mirror
1

Dear all

I have some water molecules in my system and I have defined a group with WATER name.
Also I have another molecules in the other groups.
The ID to define H-O-H angle is 2.

If I use:
fix 3 WATER shake 1e-6 1000000 0 a 1

What will happen?

I mean what is the result of using the wrong ID for angles in fix shake?

Thanks a lot for your time and attention,

Best Regards,

Nahid

2

Dear all

I have some water molecules in my system and I have defined a group with
WATER name.
Also I have another molecules in the other groups.
The ID to define H-O-H angle is 2.

If I use:
fix 3 WATER shake 1e-6 1000000 0 a 1

What will happen?

lammps will (try to) do what you tell it to do, i.e. apply an angle
constraint to all angles of type 1 in the group WATER.

I mean what is the result of using the wrong ID for angles in fix shake?

what do you expect? that lammps magically will not do what you asked
for but rather what you meant??

axel.

3

but angle 1 is not in group WATER.

So, I don’t know they constraint or not the angles of the other molecules are constraint.

how can i make sure?

thanks

Slay

4

but angle 1 is not in group WATER.

So, I don't know they constraint or not the angles of the other molecules
are constraint.

please repeat after what i wrote in my previous e-mail:

apply an angle constraint to all angles of type 1 in the group WATER

that is a definite and clear statement. if there are no angles of type
1 in the group WATER there there are no contstraint angles. this is
elementary and straightforward logic.

why should there be a constraint anywhere else??

how can i make sure?

have you bothered to look at the logfile?

axel.