Subject: adumb in charmm

From: [email-masked]
Date: Tue, 1 Oct 2002 17:26:37 -0400

Greetings,

I have a few questions about the adaptive umbrella application (adumb) 
in charmm that I was hoping someone can answer. 

i) There is a note in the ENERGY subroutine stating that the pmf is 
determined prior to the evaluation of Ewald K-space sum. There seem 
to be no mention of this in the documentations.  Has anyone else
attempted the use of Ewald sum with adumb? ..or is adumb strictly 
limited to the use of cutoffs? 
 
ii) There also seem to be a conflict between adumb and the use
of NTRFRQ during dynamics to stop trans/rotation of the system.  
The use of this flag results in a call to the ENERGY subroutine
at every NTRFRQ'th step.  Since the statistics is collected 
at every energy calls (rather than at every dynamic steps), there
is an over accounting of the umbrella coordinate at every NTRFRQ'th
step.  Has this issue perhaps been resolved in later version? (I
am using version c27b2.)

I truly appreciate any input on these matters.  Thanks.

Jano