Typical basis sets that are commonly used are parameterized and defined for lighter elements such as H, C, N, O, etc that are most relevant for small organic molecules. I agree that LANL2DZ is mainly used for calculations involving heavy elements because it is highly precedented. It is not defined for H-Ne so for many organometallic complexes it is used for heavy elements while other basis sets are defined for C, N, O etc. In reality there are better options but many people prefer to stick to what they know works. Def2DZVP, Def2TZVP, and Def2TZVPP all are better options in my opinion for organometallic complexes and in combination with functionals that include dispersion (such as NM15 or M06, for example and not BP86) are very accurate. Here is a resource that discuses the LAN basis sets: https://www.cup.uni-muenchen.de/oc/zipse/teaching/computational-chemistry-2/topics/los-alamos-national-laboratory-lanl-effective-core-potentials/
Thanks a lot, Dear, Gabriel Lovinger,
Can we use Def2DZVP, Def2TZVP, and Def2TZVPP basis sets for both transition metals (Cr, Cu etc) and as well as for C, O, H etc.?
You can, they work well for H-Kr so light elements plus first row transition metals. This chart may be helpful. https://sites.google.com/site/orcainputlibrary/basis-sets
Dear, Gabriel Lovinger,
Hope you are fine!
I am working on Cu-CO2, I tried all above your mentioned basis sets, I am facing bellow problem,
QPErr --- An ambiguous keyword was detected.
axcycle=1000 freq=noraman def2-tzvp int=
'
Last state= "Basis"
TCursr= 139352 LCursr= 34
Error termination via Lnk1e in /public/software/g09d01/g09/l1.exe at Fri Jan 5 05:24:48 2018.
Job cpu time: 0 days 0 hours 0 minutes 0.1 seconds.
File lengths (MBytes): RWF= 5 Int= 0 D2E= 0 Chk= 2 Scr= 1
2018年 01月 05日 星期五 05:24:48 CST
I am using these in input.
#p opt=maxcycle=1000 freq=noraman def2-tzvp int=ultrafine m06l scf=(novaracc,xqc,maxcycle=5000,conver=6)
kindly help me.
Hello Anand Parkash, the error message indicates that you have a syntax error in your input command line. Try changing your input line to: #p opt=(maxcycle=1000) freq=noraman int=ultrafine def2TZVP/M06 scf=(novaracc,xqc,maxcycle=5000,conver=6). There are a few things that could be wrong with your imput but my guess is the hyphen between def2 and tzvp. I'm less familiar with commands you have for the scf section of your input so I'm not sure about possible syntax errors there but if the above modification to your input does not work try:
# opt=(verytight,maxcycle=10000) int=ultrafine freq=noraman geom=connectivity M06/Def2TZVP
Let me know if that helps.
Gabriel
- Badges
- Science topic
- Similar topics
- Chemistry, Organic
- Organic