[gmx-users] Schlitter Configurational entropy 'NaN'

[tarak karmakar]

Dear All,
I wanted to calculate configurational entropy of a protein by using g_covar
and g_anaeig as follows,

g_covar -f ../traj.xtc -s ../npt_prod -o eigenval -v eigenvec.trr -av
average.pdb
g_anaeig -v eigenvec.trr -entropy -temp 300

I got the following results

The Entropy due to the Quasi Harmonic approximation is 31440.3 J/mol K
The Entropy due to the Schlitter formula is nan J/mol K

I went back to check the eigenvector file by dumping it to a new file
'dump'. There is no 'nan' indeed.

Could anyone comment on why I'm getting Schlitter entropy as 'nan'?

Thanks and regards,
Tarak