dear all,
there are errors in the code regarding 1) the equation for kappa, which
is used for the reaction field method; and 2) in the calculation of the
ionic strength.
1) in rf_util.c kappa is calculated as
*kappa = sqrt(2*I/(EPSILON0*eps_rf*BOLTZ*Temp));
but the factor 2 in the square root is only correct if the sum in the
ionic strength I is actually divided by 2, which it isn't. so the factor
2 should be omitted.
2) in force.c the ionic strength is (among others) calculated by summing
the absolute values instead of the squares of the charges.
zsq += fabs(q);
this is only correct for monovalent charge groups.
@developers: these errors have been remarked previously on the mailing
list. as it is not mentioned in the bugzilla, i thought i can bring it
up again... can you correct this in the code for the next version please?
thanks.
best regards,
daniela
--
Daniela S. Mueller
Biologist (Dipl. Biol.)
Molecular Dynamics (MD)
Groningen Biomolecular Sciences and Biotechnology Institute (GBB)
MD group website: http://www.rug.nl/gbb/md
Daniela Mueller
Dept. of Biophysical Chemistry
University of Groningen
Nijenborgh 4
9747 AG Groningen
The Netherlands
Tel.: +31 (0)50 3634327
Fax.: +31 (0)50 3634398
e-mail: [EMAIL PROTECTED]
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