For example, the def2-tzvp basis set in psi4 (psi4/share/psi4/basis) for C atom is as following:
C 0
S 6 1.00
13575.3496820 0.22245814352E-03
2035.2333680 0.17232738252E-02
463.22562359 0.89255715314E-02
131.20019598 0.35727984502E-01
42.853015891 0.11076259931
15.584185766 0.24295627626
S 2 1.00
6.2067138508 0.41440263448
2.5764896527 0.23744968655
S 1 1.00
0.57696339419 1.0000000
S 1 1.00
0.22972831358 1.0000000
S 1 1.00
0.95164440028E-01 1.0000000
P 4 1.00
34.697232244 0.53333657805E-02
7.9582622826 0.35864109092E-01
2.3780826883 0.14215873329
0.81433208183 0.34270471845
P 1 1.00
0.28887547253 1.0000000
P 1 1.00
0.10056823671 1.0000000
D 1 1.00
1.09700000 1.0000000
D 1 1.00
0.31800000 1.0000000
F 1 1.00
0.76100000 1.0000000
However, the def2-tzvp basis set that downloaded from the web of Basis Set Exchange for C atom is as following:
C 0
S 6 1.00
13575.3496820 0.22245814352D-03
2035.2333680 0.17232738252D-02
463.22562359 0.89255715314D-02
131.20019598 0.35727984502D-01
42.853015891 0.11076259931
15.584185766 0.24295627626
S 2 1.00
6.2067138508 0.41440263448
2.5764896527 0.23744968655
S 1 1.00
0.57696339419 1.0000000
S 1 1.00
0.22972831358 1.0000000
S 1 1.00
0.95164440028D-01 1.0000000
P 4 1.00
34.697232244 0.53333657805D-02
7.9582622826 0.35864109092D-01
2.3780826883 0.14215873329
0.81433208183 0.34270471845
P 1 1.00
0.28887547253 .46445822433
P 1 1.00
0.10056823671 .24955789874
D 1 1.00
1.09700000 1.0000000
D 1 1.00
0.31800000 1.0000000
F 1 1.00
0.76100000 1.0000000
The difference between them is the contraction coefficient of the second and third P shell.
Then which one should I use?
Thank you for your reply!