[gmx-users] Eigenvalues not saved from gmx covar in GROMACS 5

[Steven Morgan]

I have installed v5 of GROMACS and am doing simulations on a peptide VPGVG repeated five times.  I am trying to calculate entropy and the eigenvalues of the covariance matrix to get eigenfrequencies.  When I issue the command gmx covar -f full.trr -s full.tpr -v -o -mwa (for eigenvalues), I get an empty eigenvalues.xvg.  In GROMACS v4.5.5 I used to get the eigenvalues outputted, for the same data sets, same command (g_covar).  It says it's writing the eigenvalues, but when I open the file there are no eigenvalues there, only the preamble for the xvg file, ending at @TYPE xy.  What am I doing wrong or is this a bug?

Thank you,
-Steven