[gmx-users] g_dielectric errors for getting frequency dependent dielectric constants

[550931258 at qq.com]

Dear all,
      
       I have some questions when calculating frequency dependent dielectric constants throughg_dielectric.

1. After using " g_dipoles -corr mol " command to get the dipcorr.xvg, if I uesd " g_dielectric " program, the error is as following.
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Fatal error:
nparm = 0 in file expfit.c, line 465
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if I used " g_dielectric -eint 50 -bfit 5 -efit 100 -ffn exp ", then the error is:
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nbegin = 50, x[nbegin] = 5, tbegin = 5
Step       chi^2      Lambda          A1          A2          A3
Segmentation Fault
================

2. When I read the manul aboutg_dielectric, I have a question about the output file " epsw.xvg ". In the manul, it discribs " The second file contains the real and imaginary parts of the frequency-dependent dielectric constant ". How can I get the real parts of the frequency-dependent dielectric constant only ? 

I appreciate your help. Thanks a lot!