CHARMM Development Project Forums User Discussion & Questions Energy terms, Constraints, Restraints, and Solvation Energy inconsistency before/after SHAKE when using BLOCK

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

I later found out that this inconsistency in the single point energy does not affect the result of MD simulation.