[CP2K-user] [CP2K:21412] Difficulties converging Acetonitrile MD run

[Michela Benazzi]

Hello everyone,

I am running NPT MD on a system of 25 acetonitrile molecules at 310 K and 
cannot get it to converge.

*The purpose*: to have an equilibrate system of acetonitrile that I can 
later add to a previously equilibrated slab of liquid Ga + vacuum. The 
acetonitrile would replace the vacuum space (10.8x10.8x21 A^3), and I would 
run MD again on the new integrated unit cell.

*Some methods*:

   1. *Unit cell:* used the density of acetonitrile at 298.15 K. Boiling 
   point is 355.1 K, so I assumed the density difference would be negligible.
   2. *Periodicity:* XY to mirror the slab I will be using later (metal 
   layer + vacuum on top).
   > Perhaps I don't need to use the same periodicity?
   3. Used PBE, but did not account for Grimme D3 dispersion.
   > Because it is a polar molecule, I probably need to add for DFTD3. This 
   paper 
   <https://www.sciencedirect.com/science/article/pii/S0167732221031482#s0010> 
   mentions Coulomb F + Lennard Jones F having an effect on the potential.

I am rerunning it right now after adding DFTD3 and XYZ periodicity, but 
would still appreciate any advice. Sometimes I feel like I can "get away" 
with simplifying my system, and it only comes back to bite me later.

Thank you kindly for your help,

Michela

-- 
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 visit https://groups.google.com/d/msgid/cp2k/27d9b168-c9cb-4854-9a54-9df032d9a6aen%40googlegroups.com.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20250423/c6f361cb/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 48298480.out
Type: application/octet-stream
Size: 2099767 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20250423/c6f361cb/attachment-0002.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Picture1.png
Type: image/png
Size: 36756 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20250423/c6f361cb/attachment-0001.png>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: MeCN.xyz
Type: chemical/x-xyz
Size: 5650 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20250423/c6f361cb/attachment-0001.xyz>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: MeCN.in
Type: application/octet-stream
Size: 2669 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20250423/c6f361cb/attachment-0003.obj>