Ired crashes define

[Michael_Patzschke]

Hello,

I am trying to define internal coordinates with ired, but this results in a crash. I have tried to change the offending structure slightly, I have preoptimized the structure using xtb. I have run an optimisation using cartesian coordinates. But whatever I try, I get the same error. The message is as follows:

Code Select Expand


ired
     geoired.f after prepare_subunits.f
        final subunits_late   F
      nsub    1
        final exact_ortho   F
     START LOOP OVER SUBUNITS

internal coordinate no.      2
:


this <bend> is a very straight one, really !

INTERNAL COORDINATE     2 BECAME ILL-CONDITIONED !

========================
internal module stack:
------------------------
    define
    geospy
    geoired
========================

allcas: INTERNAL COORDINATE IS ILL-CONDITIONED
define ended abnormally
define ended abnormally
program stopped.


I would be grateful for any information, how to circumvent the problem.

Best regards,
Michael

[Arnim]

Hello,

you could try use a different metric and then run define again.
Like this:
$redund_inp
  metric n

with n= -3...3

Cheers
Arnim

[Michael_Patzschke]

Hello Arnim,

thank you very much for your fast reply. The metric -3 did the trick! I had seen an earlier question in the forum where a similar problem was reported and solved by using metric 1. But I was not aware, that negative values were an option...

Anyway, the optimisation runs smoothly now and I am grateful for the help.

Kind regards,
Michael