[gmx-users] Result difference between Gromacs and other pakages, is it a bugs??(oplsaa)

PeiQuan Chen gromacs at 163.com
Wed Jun 11 13:05:01 CEST 2003

Dear gmx-users:
>  Have you done an exact comparison of parameters?
  Yes. I also use the gmxdump -s topol.tpr to check the parametes.
The following is part of the file:

            functype[0]=LJ, c6= 2.03186437e-03, c12= 3.73510579e-06
            functype[1]=LJ, c6= 4.99228307e-04, c12= 3.34443996e-07
            functype[2]=LJ, c6= 4.99228307e-04, c12= 3.34443996e-07
            functype[3]=LJ, c6= 1.22660160e-04, c12= 2.99463281e-08
            functype[4]=BONDS, b0A= 1.09000e-01, cbA= 2.84702e+05, b0B= 1.09000e-01, cbB= 2.84702e+05
            functype[5]=ANGLES, thA= 1.07800e+02, ctA= 2.76329e+02, thB= 1.07800e+02, ctB= 2.76329e+02

            nr: 12
            multinr[division over processors]: 12
               0 type=4 (BONDS) 0 1
               1 type=4 (BONDS) 0 2
               2 type=4 (BONDS) 0 3
               3 type=4 (BONDS) 0 4
  The parametes is just as the same I have used in tinker expect for the unit. And I have give the final 
conformation after em. the C-Cl bonds is not equal as I have got using tinker.
  The four C-Cl bond distances is 1.090000 1.081665 1.091833  1.091833, which tinker result is four 1.09000.
Do you think whether is a precision problem?

Sincerely yours
PeiQuan Chen
PeiQuan Chen 	Department of Chemistry, Nankai University
WeiJin Road 94, TianJin, 300071, P.R.China
phone:	(86)2223506728		Mobile Phone: (+86)13920675030
gromacs at 163.com	

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