> Deal All, > I know tried to replace the V atom with a C instead. After many CG steps, > the same problem in the SCF run suddenly occured. Can it be an issue of > compilation? > > -Joachim
Dear Joachim, let's be systematic: 1) can you please confirm that the problem is not due to what I suggested to check several days ago - the maximal spin set up by default on ALL atoms? 2) does the electronic structure (either with V, or without) - position of carbon 2s and 2p bands, charges - remains reasonable until "the same problem in the SCF run suddenly occured"? Or are you having weird results all the way through and only notice it when they start to diverge? Sorry... 3) what happens "afer many CG steps" it terms of structure; in which respect does the crashed structure differ from the good one? You may have the .ANI file stored, or just .XV files from the beginning and from immediately before the crash. If it happens "suddenly" then some crazy forces calculated on atoms might be responsible, whatever the reason for this. Good luck Andrei