Hi everyone,

I am calculating just some small molecules in adduct formation and for some of them I encounter the following problem when setting up the Hückel matrix during the define step:

ERROR: non-positive definite matrix in Cholesky decomposition (routine: usad)

of overlap matrix in project.f

MODTRACE: no modules on stack

negative root in usad, see output

define ended abnormally

Has anyone of you an idea, what the problem could be?

Thanks.