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Posted By: mbh High frequency correction energy - 07/24/06 04:45 PM
Hi All,

Could somebody please tell me what exactly "high frequency correction energy" means? I mean the EHFC term in the energy output. I am trying to run a simulation uisng HARMonic constraint, but the EHFC, and so the total energy, keeps decreasing. Any help would be appreciated.
Posted By: rmv Re: High frequency correction energy - 07/24/06 05:14 PM
EHFC is a modest correction to energy due to high frequency motions; it's more likely to be a symptom, rather than the cause of problems from a simulation with harmonic restraints. The restraints are the more likely cause of instability, and probably need to be changed.
Posted By: mbh Re: High frequency correction energy - 07/24/06 06:55 PM
Hi Eric,

Thank you so much for replying.
Do you mean that whenever this term is large, something is wrong (even if it is constant)?
Thanks again
Posted By: rmv Re: High frequency correction energy - 07/24/06 07:35 PM
Probably, although it's hard to generalize out of context. It should be a small fraction of the potential, and smaller than e.g. the DIHE term.
Posted By: lamourgu Re: High frequency correction energy - 07/24/06 08:01 PM
Are you using the DYNA VV2 integrator with thermostats (TPCONTROL)? In that case, the EHFC terms contains more than the usual: It also has the energy content of the heat bath -- which may decrease steadily if you put external couplings such as HARM.

Look at this post for more information.

Guillaume
Posted By: mbh Re: High frequency correction energy - 07/24/06 08:57 PM
Hi Guillaume,
I am using VVER with NOSE temperature control. Does this make any difference?
Posted By: rmv Re: High frequency correction energy - 07/24/06 09:05 PM
Perhaps, and you should consider using some other method for T control. The VVER integrator is not very good, but features are hardly ever removed from CHARMM.
Posted By: hiva Re: High frequency correction energy - 04/23/11 07:13 PM
Good, I was wondering about this term. So, how HFCTote and TOTEner are related? I see that in my log file HFCTote is not a small number, in fact it is as great as TOTEner.
Posted By: lennart Re: High frequency correction energy - 04/24/11 08:56 PM
HFCT is the corrected total energy, not the correction, thus HFCT and TOTE are very similar; HFCT will be more (slightly more) stable over time.
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