[CP2K-user] [CP2K:19525] Problem when combining coordination numbers as one collective variable

[Xu Wang]

Dear CP2K developers,
    I'm trying to use the &COMBINE_COLVAR section in CP2K (version 2022.1) 
to combine two coordination numbers as one collective variable (CV), and 
output the Lagrange multipliers of this CV. However, I encounter problems 
in both the AIMD simulation and the Lagrange multipliers. I update an input 
file as an example to explain these problems. The input file is for an AIMD 
simulation of a simple system containing 64 water molecules. The difference 
between the O-H coordination numbers of the O atoms in two water molecules 
is chosen as the CV (by using the &COMBINE_COLVAR section). It is 
reasonable to set the difference to be zero, i.e., these two O atoms have 
same O-H coordination numbers.
    However, after each MD step, CP2K output several warnings with same 
text:
[image: WARNING.png]
More seriously, all outputted Lagrange multipliers (both Shake and Rattle) 
are equal to zero:
[image: ZERO.png]
I am wondering if there are any problems in my input file, or in CP2K?
Sincerely,
Xu Wang

-- 
You received this message because you are subscribed to the Google Groups "cp2k" group.
To unsubscribe from this group and stop receiving emails from it, send an email to cp2k+unsubscribe at googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/cp2k/7acfb13f-f057-4019-a4fe-7577e5a79dd4n%40googlegroups.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20231116/b0a84f42/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 64H2O_CV-CN.inp
Type: chemical/x-gamess-input
Size: 11860 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20231116/b0a84f42/attachment-0001.inp>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ZERO.png
Type: image/png
Size: 11754 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20231116/b0a84f42/attachment-0002.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: WARNING.png
Type: image/png
Size: 8604 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20231116/b0a84f42/attachment-0003.png>