[gmx-users] How to calculate Pseudo dihedral angle as a function of time.

[Kartheek]

Hi everyone,
I wanted to calculate pseudo dihedral angle as a function of time for a BDNA system. GROMACS g_angle gives dihedral as a function of time for only four connected atoms not for groups. I have defined four groups, each group consist of COM of set of atoms. defined as follows in plumed format g1,g2,g3,g4 are four groups(these are not connected). any help will be appreciated. 
g1
1998 1999 2001 2003 2004 2005 2006 2007
2375 2376 2377 2380 2381 2382 2384 2385 2386 2387 2388

g2
1986 1989 1990 1993 1995 1996 2010 2013 2015

g3
1949 1952 1953 1956 1958 1959 1980 1983 1985 

g4
1961 1962 1963 1966 1967 1968 1970 1971 1972 1976 1977 1978
 

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Sincerely,
P.Kartheek,
Research Scholar.