Firefly and PC GAMESS-related discussion club

Learn how to ask questions correctly  
We are NATO-free zone

RO-B3LYP crashes at the first SCF cycle for radical-anions of H-NO2 and Me-NO2


Dear colleagues,

After facing problem with convergence of RO-B3LYP for anion-radical of 2-nitropropane in 6-31++G** basis, ( ) I check if this problem appears with simpler systems - and it does.

First, I check nitromethane radical-anion, and problem does exist for both possible conformation - with one CH-bond eclipsing N-O bond (a minimum for neutral nitromethane for B3LYP/6-31++G** and MP2/6-31++G**, but transition state for HF/6-31++G** ) and with one C-H bond perpendicular to nitro group (minimum for HF/6-31++G**)

Second, I replaced methyl group for hydrogen atom - the simplest system still cause the same problem, no convergence of SCF at the first cycle.

Input file for H-NO2 is attached

Please, give advice how to cope with this problem, I'm quite interested in comparision of a series of radical-anion with NO2-moiety

This message contains the 1 kb attachment
[ HNO2-radan_RO-B3LYP.inp ] input-file for H-NO2 radical-anion

[ Previous ] [ Next ] [ Index ]           Sat Jan 10 '15 9:36pm
[ Reply ] [ Edit ] [ Delete ]           This message read 1035 times