A researcher here has found some interesting issues with Molpro2002.6.
She starts with a single geometry, open shell. On occasion she finds that the HF part converges to a higher energy relative to closely related geometries. She seems to be able to overcome this by employing a dft guess for the uccsd(t) calculation.
Now,
(1) If she does: dft, hf, uccsd(t) calculation she obtains one answer.
(2) If she does: uhf, hf, uccsd(t) she gets an answer that sometimes is not the same as in (1) usually for higher energy type structures.
(3) If she does: hf, hf, uccsd(t) she get an answer that is different again from (1) on occasion, by up to 0.01 Hartree.
Could anyone help out and tell us what is going on here. SCF convergence is set to 10^-12.
Thanks heaps.
tony _______________________________________________________ Dr. Anthony P. Scott, Computational Quantum Chemistry Gp, Office Ph.: 61-2-6125-3573 Research School of Chemistry, Dept. Ph.: 61-2-6125-3637 Australian National University, Fax: 61-2-6125-0750 Canberra, ACT 0200, AUSTRALIA.
E-mail: [EMAIL PROTECTED] _______________________________________________________
