Which is the best basis set for geometry optimization and finding the energy gap of the metal cationic complexes wherein chloride ion is outside the coordination sphere? For neutral complexes, B3LYP functional with LanL2DZ is considered for the same application. But the Gaussian program with the similar basis set in case of cationic complexes is getting terminated abruptly.
Can you post either your input file or the error message?
A starter would be, what multiplicity did you set for the charged complex? If it's closed-shell as a neutral, it will be doublet or maybe quadruplet as a charged one.
There might be that you are not using effective core potential or you are missing some elements. May be spin multiplicity and charge is inaccurate.
If you are using gaussView as visual interface, it can help you to maintain multiplicity automatically when charge is changed.
Jürgen Weippert & Rachita Panigrahi .
error message is :
Density matrix is not changing but DIIS error= 8.55D-05 CofLast= 2.45D-01.
>>>>>>>>>> Convergence criterion not met.
SCF Done: E(UB3LYP) = -1434.20446806 A.U. after 129 cycles
Convg = 0.1492D-05 -V/T = 2.0655
= 0.0000 = 0.0000 = 0.5000 = 0.7525 S= 0.5012
= 0.000000000000E+00
Annihilation of the first spin contaminant:
S**2 before annihilation 0.7525, after 0.7500
Convergence failure -- run terminated.
I had set Charge = 1 Multiplicity = 2 (doublet) in the calculation setup. Jürgen Weippert
OK, so the SCF gets actually going but doesn't converge. You could try operating in two steps:
1) Optimize SCF and structure with weakened convergence criteria.
2) Increase the convergence criteria and restart the optimization. Sometimes the SCF has trouble to converge if the starting structure is somewhat bad and the error goes away by changing that.
Nithya Balakrishnan first, whenever you encounter SCF convergence failure message as output, so, you have to look the progress of the SCF by using #P in place of # which print the status of each iteration step. it is very helpful to know the SCF is converging slowly or not .
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Carbon Materials
- Graphite
- Graphene