Previous Thread
Next Thread
Print Thread
Joined: Jan 2022
Posts: 2
Y
ytao Offline OP
Forum Member
OP Offline
Forum Member
Y
Joined: Jan 2022
Posts: 2
Hi there, I would like to ask a question about BLOCK module.

I'm using the BLOCK module in the CPU version of charmm (c47a1). I set up a three-block system and planned to run dynamics.
I was curious about the energy, therefore I called ENERgy before and after SHAKE (e.g. shake fast bonh param) before calling DYNA, then I found the two energies are different.

For example
before SHAKE:
ENER> 0-100167.71864 -7729.19789 6.88043
ENER INTERN> 4214.68967 3553.10667 271.98621 2030.41904 123.21122
ENER CROSS> -332.41288 0.00000 0.00000 0.00000
ENER EXTERN> 4828.07698 -86424.22023 0.00000 0.00000 0.00000
ENER IMAGES> 239.97592 -7390.48494 0.00000 0.00000 0.00000
ENER EWALD> 531.32747-505978.20960 484163.23345 0.00000 0.00000
ENER RESTR> 1.58238 0.00000 0.00000 0.00000 0.00000

after SHAKE:
ENER> 0 -95831.08338 -4336.63526 6.47747
ENER INTERN> 1079.16927 1598.97023 271.38280 2029.76266 122.77658
ENER CROSS> -332.77976 0.00000 0.00000 0.00000
ENER EXTERN> 4780.01659 -78725.23657 0.00000 0.00000 0.00000
ENER IMAGES> 231.78886 -6673.17411 0.00000 0.00000 0.00000
ENER EWALD> 548.58184-505978.20960 485214.28512 0.00000 0.00000
ENER RESTR> 1.58271 0.00000 0.00000 0.00000 0.00000

I also checked other systems without using BLOCK module, and two energies are consistent.
In addition, if I use "ENERgy omm", the two energies are almost identical.

Please feel free to advise. Thanks.

YT

Joined: Jan 2022
Posts: 2
Y
ytao Offline OP
Forum Member
OP Offline
Forum Member
Y
Joined: Jan 2022
Posts: 2
I later found out that this inconsistency in the single point energy does not affect the result of MD simulation.


Moderated by  BRBrooks, lennart, rmv 

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.3.31-1~deb10u1 Page Time: 0.007s Queries: 18 (0.004s) Memory: 0.7289 MB (Peak: 0.7698 MB) Data Comp: Off Server Time: 2022-11-29 15:31:41 UTC
Valid HTML 5 and Valid CSS