[gmx-users] units of the bonding parameters in the .itp file

Andrey V Golovin golovin at genebee.msu.su
Wed Aug 4 20:34:18 CEST 2004

Dear Aina,

AQ> could anybody tell me which are the units of ffG43a2bon.itp? for the bond
AQ> parameters? i mean bg_XX?

For my first look things looks like :
#define gb_1        0.1000  1.5700e+07
                     b (nm)

F= Kj/mol/nm = k*(r^2-b^2)*r = k*nm^3= m(au)nm^2 = 1.6e-27*1e-18
according to ci (se)(i don't know exactly that is spelling)
k*1e-27 = 1.6e-27*1e-18
but in gromacs F*1e9=F(ci)
so K*1e-27*1e-9 = 1.6e-27*1e-18
from that k something about 1e7 (because b=0.1) look likes from itp

mmm hope it will give some idea. =)

look et 2.2 and 4.2.1 of manual

Best regards,
 Andrey                            mailto:golovin at genebee.msu.su

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