Molcas Forum

daishudaishu

Member

Registered: 2019-02-24

Posts: 22

How to use ECP in def2 basis

Dear all,
I am calculating CH3I with def2-tzvp basis. I believe that MOLCAS is doesn't see the ECP part of the basis. So the total number of electrons is still 62. And the Kohn-Sham orbitals are messed up. How to force MOLCAS to use the ECP of the def2-tzvp basis?

Thanks a lot!

&GATEWAY  &END
  Title= molecule
  coord  = CH3I-001.xyz
  basis  = DEF2-TZVP ;  group=  E
  AMFI
RICD
SDIP
ANGM
 0. 0. 0.
End of Input
&SEWARD
&SCF
PROR = 2 3

KSDFT=PBE0

&GRID_IT
all

nikolay

Member

From: Stuttgart

Registered: 2016-03-21

Posts: 54

Re: How to use ECP in def2 basis

I think there is a mistake in the basis set library. As you say, the ecp electrons are not subtracted from the total.
This simple patch should fix it:

--- a/basis_library/DEF2-TZVP
+++ b/basis_library/DEF2-TZVP
@@ -881,7 +881,7 @@ Basis set for iodine
 /I.DEF2-TZVP..11s10p8d2f.6s5p3d2f.ecp28.
 F. Weigend and R. Ahlrichs, Phys. Chem. Chem. Phys. 7, 3297 (2005)
 IODINE       (11s,10p,8d,2f) -> [6s,5p,3d,2f]
-          53.   3
+          25.   3
 * S-type functions
     11    6
            5899.5791533

Same behavior is there at https://www.basissetexchange.org for any ECP, probably not correct for "inline" basis set as well and should be fixed there.