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Reinaldo Pis Diez
reinaldo.pisdiez@gmail.com

I'm using Firefly 7.1.G, build number 5618, to study a system containing about a hundred atoms. I'm using cartesian coordinates due to construction issues. Scf is ok, slow but convergent. Now, I have to optimize the neighborhood of a given atom, so I decide to use nzvar=3M-6 in $contrl, and "build" the z matrix in $zmat using zmat(1)=1,1,2, etc, etc. I've checked the z matrix and is ok with respect to connectivity issues.
Despite the ifreez option I'm using to freeze almost all the internal coordinates, Firefly returns an error message during the reading of the z matrix in check mode:

  --- ENCODED Z MATRIX ---
COORD    TYPE     I    J    K    L    M    N
    1       1     2    1
    2       1     3    1
...
  309       3   105   69   33   21
ROUNDOFF ERROR IN BEND - STOP

where the 309th coord is the last one. What is the source of that error? (Almost) linear bond or torsion angles perhaps?
I could provide the entire input if needed.
Thanks in advance.
Regards,

Reinaldo