We calculated interaction energy of all optimized adducts applying counterpoise corrected method based on the basis set superposition error (BSSE) at B3LYP/6-31G(d,p) and B3LYP/6-311++G(2d,3p) levels of theory, respectively [23, 24].
The error associated with dispersion interactions can be lessened by using smaller basis sets, which make the AB structure more stable than A and B separately using the basis set superposition error (BSSE).
It is well known that calculations of complexation energies are always shadowed by the basis set superposition error
(BSSE, artificial lowering of the total energy of the complex that arises from the mathematical fact that the basis sets are not complete and thus the basis functions of one component of the complex are available for the description of the electron density of the second one ).
We applied the counterpoise method [31, 32] to calculate the basis set superposition error using the equation:
Using (1) and (2), respectively, the binding energy, basis set superposition error (BSSE), and dispersion energy were calculated for the dopasilica system.
It is well known that complexation energies calculated in such a way may be seriously affected by the artificial lowering of the energy of the complex due to the basis set superposition error
(BSSE) (see e.g.
The resulting [E.sub.int] values are corrected for the basis set superposition error by utilizing a counterpoise correction .
The CCSD(T)/def2-QZVPP+mb values of [E.sub.int] are corrected for the basis set superposition error .