Dear all,
I want to make some comparison for the CO and N2 ligand. The overall molecular structure is like LM(N2)(CO), where L is the ligand, and M is the transition metal.
So for one calculation, I assign the fragment as LM(N2)-CO, and for the other calculation the fragment is between LM(CO)-N2.
But when I compare the energies, I got:
Total_HF Total_SAPT0 Electrostatics Exchange Induction Dispersion
frag-A -237.05977386 -364.84428525 -279.74545570 450.29901873 -407.61333689 -127.78451139
frag-B -87.12775551 -187.79711231 -149.59754830 298.94767985 -236.47788705 -100.66935680
The energies are quite different.
I thought the total_HF should be the same, but it turns out not. Is that because I cut the “single bond” between the metal and the N2 or CO ligand?
otherwise, what is the problem?
Many thanks for your help.
Below is my input:
molecule water_dimer {
0 1
C -2.26410881361870 -1.38764221864452 -0.57276669195807
C -1.57591892544698 -2.04084039980690 0.48707801581458
C -0.22131582962187 -2.27877985140471 0.05373986858759
C -0.09328136986731 -1.76496958830631 -1.26780127679264
C -1.35188096701738 -1.20326699416948 -1.66593400599147
H -3.29831852097010 -1.07206037394808 -0.55519821775797
H -1.99796476328665 -2.32197915950578 1.44195786648649
H 0.55303440517172 -2.77356443807344 0.62314169063338
H 0.80509682656840 -1.78612745429576 -1.86948982285817
H -1.58406347307862 -0.76982774950890 -2.62778699352737
C -1.70270658933757 1.56796518950956 0.15225479109865
O -2.44977340019730 2.45961794225472 0.11710002872934
Re -0.56734579293026 0.01030065045406 0.11549064847753
N 0.03964318954637 0.33545734639531 1.97108247470505
N 0.37231387861758 0.43303375080676 3.03984970348604
–
0 1
C 0.85904649296205 1.09200542925635 -0.59941634142548
O 1.72214365250662 1.68581791898718 -1.10625173770747
units angstrom
no_reorient
symmetry c1
}
basis {
assign Re vdz-pp
assign C jun-cc-pvdz
assign H jun-cc-pvdz
assign O jun-cc-pvdz
assign N jun-cc-pvdz
}
energy(‘sapt0’)