Multiwfn forum

saeed_E

Member

Registered: 2019-12-21

Posts: 311

About sobEDA calculations....

Dear Tian,
A moment ago, I calculated the value of interaction energy (delta_E_int) for an A...B complex optimized at B3LYP-D3(BJ)/6-311+G(2d,p) level using G16. However, sobEDA was also used to recalculate the interaction energy exactly at the same level. Since both levels are quite the same, I expected to obtain quite identical values for delta_E_int. But, there is a somewhat difference; that is, delta_E_int from G16 is -9.29 kcal/mol while delta_E_int from sobEDA is -8.82 kcal/mol, rendering a difference by 0.47 kcal/mol in absolute. Could you please let me know the source of such a difference?

Sincerely,
Saeed

sobereva

Tian Lu (Multiwfn developer)

From: Beijing

Registered: 2017-09-11

Posts: 2,011

Website

Re: About sobEDA calculations....

Dear Saeed,

The mechanism of the sobEDA shell script is completely transparent to users. I suggest manually comparing keywords in the .gjf and energy in the .out file, between the files produced by the script and those you manually obtained. You should find more details about the difference. If all keywords were properly used, and all calculations converged to the most stable wavefunctions, the obtained interaction energies should be the same.

Best,

Tian

saeed_E

Member

Registered: 2019-12-21

Posts: 311

Re: About sobEDA calculations....

Dear Tian,
Many thanks for your very valuable guidance.

Best regards,
Saeed